diff --git a/.idea/misc.xml b/.idea/misc.xml
index 74dd639..991a888 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="jbr-21" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="temurin-21" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/README.md b/README.md
index 64f32fe..9286bcd 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,8 @@ Ensure your MariaDB database has the following tables:
 -- Table for SAIs
 CREATE TABLE SAIs (
     id_sai INT AUTO_INCREMENT PRIMARY KEY,
-    ns VARCHAR(255) NOT NULL
+    ns VARCHAR(255) NOT NULL UNIQUE,
+    modelo VARCHAR(255)
 );
 
 -- Table for Batteries
diff --git a/app/src/main/java/com/example/saipp/data/SaiRepository.kt b/app/src/main/java/com/example/saipp/data/SaiRepository.kt
index 0533e5f..8cd7b4f 100644
--- a/app/src/main/java/com/example/saipp/data/SaiRepository.kt
+++ b/app/src/main/java/com/example/saipp/data/SaiRepository.kt
@@ -1,25 +1,24 @@
 package com.example.saipp.data
 
-import android.util.Log
 import com.example.saipp.data.model.Sai
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import java.sql.SQLException
 
 class SaiRepository {
-    companion object {
-        private const val TAG = "SaiRepository"
-    }
-
     suspend fun getAll(): Result<List<Sai>> = withContext(Dispatchers.IO) {
         val connection = MariaDbConnection.getConnection() ?: return@withContext Result.failure(Exception("db_connection_error"))
         try {
-            val sql = "SELECT id_sai, ns FROM SAIs"
+            val sql = "SELECT id_sai, ns, modelo FROM SAIs"
             val statement = connection.prepareStatement(sql)
             val resultSet = statement.executeQuery()
             val sais = mutableListOf<Sai>()
             while (resultSet.next()) {
-                sais.add(Sai(id = resultSet.getInt("id_sai"), ns = resultSet.getString("ns")))
+                sais.add(Sai(
+                    id = resultSet.getInt("id_sai"), 
+                    ns = resultSet.getString("ns"),
+                    modelo = resultSet.getString("modelo")
+                ))
             }
             Result.success(sais)
         } catch (e: SQLException) {
@@ -29,12 +28,32 @@ class SaiRepository {
         }
     }
 
-    suspend fun insert(ns: String): Result<Unit> = withContext(Dispatchers.IO) {
+    suspend fun isNsRegistered(ns: String): Result<Boolean> = withContext(Dispatchers.IO) {
         val connection = MariaDbConnection.getConnection() ?: return@withContext Result.failure(Exception("db_connection_error"))
         try {
-            val sql = "INSERT INTO SAIs (ns) VALUES (?)"
+            val sql = "SELECT COUNT(*) FROM SAIs WHERE ns = ?"
             val statement = connection.prepareStatement(sql)
             statement.setString(1, ns)
+            val resultSet = statement.executeQuery()
+            if (resultSet.next()) {
+                Result.success(resultSet.getInt(1) > 0)
+            } else {
+                Result.success(false)
+            }
+        } catch (e: SQLException) {
+            Result.failure(e)
+        } finally {
+            connection.close()
+        }
+    }
+
+    suspend fun insert(ns: String, modelo: String?): Result<Unit> = withContext(Dispatchers.IO) {
+        val connection = MariaDbConnection.getConnection() ?: return@withContext Result.failure(Exception("db_connection_error"))
+        try {
+            val sql = "INSERT INTO SAIs (ns, modelo) VALUES (?, ?)"
+            val statement = connection.prepareStatement(sql)
+            statement.setString(1, ns)
+            statement.setString(2, modelo)
             if (statement.executeUpdate() > 0) Result.success(Unit)
             else Result.failure(Exception("no_rows_inserted"))
         } catch (e: SQLException) {
@@ -47,10 +66,11 @@ class SaiRepository {
     suspend fun update(sai: Sai): Result<Unit> = withContext(Dispatchers.IO) {
         val connection = MariaDbConnection.getConnection() ?: return@withContext Result.failure(Exception("db_connection_error"))
         try {
-            val sql = "UPDATE SAIs SET ns = ? WHERE id_sai = ?"
+            val sql = "UPDATE SAIs SET ns = ?, modelo = ? WHERE id_sai = ?"
             val statement = connection.prepareStatement(sql)
             statement.setString(1, sai.ns)
-            statement.setInt(2, sai.id)
+            statement.setString(2, sai.modelo)
+            statement.setInt(3, sai.id)
             if (statement.executeUpdate() > 0) Result.success(Unit)
             else Result.failure(Exception("update_failed"))
         } catch (e: SQLException) {
@@ -78,12 +98,16 @@ class SaiRepository {
     suspend fun getById(id: Int): Result<Sai> = withContext(Dispatchers.IO) {
         val connection = MariaDbConnection.getConnection() ?: return@withContext Result.failure(Exception("db_connection_error"))
         try {
-            val sql = "SELECT id_sai, ns FROM SAIs WHERE id_sai = ?"
+            val sql = "SELECT id_sai, ns, modelo FROM SAIs WHERE id_sai = ?"
             val statement = connection.prepareStatement(sql)
             statement.setInt(1, id)
             val resultSet = statement.executeQuery()
             if (resultSet.next()) {
-                Result.success(Sai(id = resultSet.getInt("id_sai"), ns = resultSet.getString("ns")))
+                Result.success(Sai(
+                    id = resultSet.getInt("id_sai"), 
+                    ns = resultSet.getString("ns"),
+                    modelo = resultSet.getString("modelo")
+                ))
             } else {
                 Result.failure(Exception("not_found"))
             }
diff --git a/app/src/main/java/com/example/saipp/data/model/Sai.kt b/app/src/main/java/com/example/saipp/data/model/Sai.kt
index bdcf3fc..786c977 100644
--- a/app/src/main/java/com/example/saipp/data/model/Sai.kt
+++ b/app/src/main/java/com/example/saipp/data/model/Sai.kt
@@ -2,5 +2,6 @@ package com.example.saipp.data.model
 
 data class Sai(
     val id: Int = 0,
-    val ns: String
+    val ns: String,
+    val modelo: String? = null
 )
diff --git a/app/src/main/java/com/example/saipp/ui/Components.kt b/app/src/main/java/com/example/saipp/ui/Components.kt
index c8f190c..f503717 100644
--- a/app/src/main/java/com/example/saipp/ui/Components.kt
+++ b/app/src/main/java/com/example/saipp/ui/Components.kt
@@ -2,19 +2,80 @@ package com.example.saipp.ui
 
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.shape.CircleShape
-import androidx.compose.material3.AlertDialog
-import androidx.compose.material3.Button
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Surface
-import androidx.compose.material3.Text
-import androidx.compose.material3.TextButton
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.QrCodeScanner
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.*
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.Dialog
+import androidx.compose.ui.window.DialogProperties
 import com.example.saipp.R
+import com.example.saipp.ui.scanner.BarcodeScannerView
+
+@Composable
+fun SearchBar(
+    query: String,
+    onQueryChange: (String) -> Unit,
+    modifier: Modifier = Modifier,
+    onScanClick: (() -> Unit)? = null
+) {
+    OutlinedTextField(
+        value = query,
+        onValueChange = onQueryChange,
+        modifier = modifier.fillMaxWidth(),
+        placeholder = { Text(stringResource(R.string.placeholder_search)) },
+        leadingIcon = { Icon(Icons.Default.Search, contentDescription = null) },
+        trailingIcon = {
+            if (onScanClick != null) {
+                IconButton(onClick = onScanClick) {
+                    Icon(
+                        imageVector = Icons.Default.QrCodeScanner,
+                        contentDescription = stringResource(R.string.scan_to_search)
+                    )
+                }
+            }
+        },
+        singleLine = true,
+        shape = MaterialTheme.shapes.medium
+    )
+}
+
+@Composable
+fun ScannerDialog(
+    onDismiss: () -> Unit,
+    onCodeScanned: (String) -> Unit
+) {
+    Dialog(
+        onDismissRequest = onDismiss,
+        properties = DialogProperties(usePlatformDefaultWidth = false)
+    ) {
+        Surface(
+            modifier = Modifier.fillMaxSize(),
+            color = MaterialTheme.colorScheme.background
+        ) {
+            Box(modifier = Modifier.fillMaxSize()) {
+                BarcodeScannerView(onBarcodeDetected = { code ->
+                    onCodeScanned(code)
+                    onDismiss()
+                })
+                
+                TextButton(
+                    onClick = onDismiss,
+                    modifier = Modifier
+                        .align(Alignment.TopStart)
+                        .padding(16.dp)
+                ) {
+                    Text(stringResource(R.string.button_close), color = Color.White)
+                }
+            }
+        }
+    }
+}
 
 @Composable
 fun ResultDialog(
diff --git a/app/src/main/java/com/example/saipp/ui/management/AddAssignmentScreen.kt b/app/src/main/java/com/example/saipp/ui/management/AddAssignmentScreen.kt
index aa18886..19b45da 100644
--- a/app/src/main/java/com/example/saipp/ui/management/AddAssignmentScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/AddAssignmentScreen.kt
@@ -1,9 +1,12 @@
 package com.example.saipp.ui.management
 
 import android.widget.Toast
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.*
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.CalendarMonth
+import androidx.compose.material.icons.filled.QrCodeScanner
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
@@ -17,7 +20,10 @@ import com.example.saipp.data.SaiRepository
 import com.example.saipp.data.model.Assignment
 import com.example.saipp.data.model.Person
 import com.example.saipp.data.model.Sai
+import com.example.saipp.ui.ScannerDialog
 import kotlinx.coroutines.launch
+import java.text.SimpleDateFormat
+import java.util.*
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -32,20 +38,83 @@ fun AddAssignmentScreen(
     
     var selectedSaiId by remember { mutableStateOf<Int?>(null) }
     var selectedPersonId by remember { mutableStateOf<Int?>(null) }
-    var assignedDate by remember { mutableStateOf("") }
-    var returnDate by remember { mutableStateOf("") }
+    
+    var assignedDateDisplay by remember { mutableStateOf("") }
+    var assignedDateDb by remember { mutableStateOf("") }
+    var returnDateDisplay by remember { mutableStateOf("") }
+    var returnDateDb by remember { mutableStateOf("") }
     
     var sais by remember { mutableStateOf<List<Sai>>(emptyList()) }
     var people by remember { mutableStateOf<List<Person>>(emptyList()) }
     var isSaving by remember { mutableStateOf(false) }
     var saiExpanded by remember { mutableStateOf(false) }
     var personExpanded by remember { mutableStateOf(false) }
+    
+    var showAssignedDatePicker by remember { mutableStateOf(false) }
+    var showReturnDatePicker by remember { mutableStateOf(false) }
+    var showQuickScanner by remember { mutableStateOf(false) }
+
+    val assignedDatePickerState = rememberDatePickerState()
+    val returnDatePickerState = rememberDatePickerState()
 
     LaunchedEffect(Unit) {
         saiRepository.getAll().onSuccess { sais = it }
         personRepository.getAll().onSuccess { people = it }
     }
 
+    if (showAssignedDatePicker) {
+        DatePickerDialog(
+            onDismissRequest = { showAssignedDatePicker = false },
+            confirmButton = {
+                TextButton(onClick = {
+                    assignedDatePickerState.selectedDateMillis?.let { millis ->
+                        val date = Date(millis)
+                        assignedDateDisplay = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault()).format(date)
+                        assignedDateDb = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(date)
+                    }
+                    showAssignedDatePicker = false
+                }) { Text("Aceptar") }
+            },
+            dismissButton = {
+                TextButton(onClick = { showAssignedDatePicker = false }) { Text("Cancelar") }
+            }
+        ) { DatePicker(state = assignedDatePickerState) }
+    }
+
+    if (showReturnDatePicker) {
+        DatePickerDialog(
+            onDismissRequest = { showReturnDatePicker = false },
+            confirmButton = {
+                TextButton(onClick = {
+                    returnDatePickerState.selectedDateMillis?.let { millis ->
+                        val date = Date(millis)
+                        returnDateDisplay = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault()).format(date)
+                        returnDateDb = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(date)
+                    }
+                    showReturnDatePicker = false
+                }) { Text("Aceptar") }
+            },
+            dismissButton = {
+                TextButton(onClick = { showReturnDatePicker = false }) { Text("Cancelar") }
+            }
+        ) { DatePicker(state = returnDatePickerState) }
+    }
+
+    if (showQuickScanner) {
+        ScannerDialog(
+            onDismiss = { showQuickScanner = false },
+            onCodeScanned = { code ->
+                val matchingSai = sais.find { it.ns.equals(code, ignoreCase = true) }
+                if (matchingSai != null) {
+                    selectedSaiId = matchingSai.id
+                } else {
+                    Toast.makeText(context, "SAI no encontrado: $code", Toast.LENGTH_SHORT).show()
+                }
+                showQuickScanner = false
+            }
+        )
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
@@ -75,6 +144,14 @@ fun AddAssignmentScreen(
                     onValueChange = {},
                     readOnly = true,
                     label = { Text(stringResource(R.string.label_sai)) },
+                    leadingIcon = {
+                        IconButton(onClick = { showQuickScanner = true }) {
+                            Icon(
+                                imageVector = Icons.Default.QrCodeScanner,
+                                contentDescription = "Escanear SAI"
+                            )
+                        }
+                    },
                     trailingIcon = { ExposedDropdownMenuDefaults.TrailingIcon(expanded = saiExpanded) },
                     modifier = Modifier.menuAnchor().fillMaxWidth()
                 )
@@ -129,19 +206,31 @@ fun AddAssignmentScreen(
             Spacer(modifier = Modifier.height(16.dp))
             
             OutlinedTextField(
-                value = assignedDate,
-                onValueChange = { assignedDate = it },
+                value = assignedDateDisplay,
+                onValueChange = {},
+                readOnly = true,
                 label = { Text(stringResource(R.string.label_assigned_date)) },
-                modifier = Modifier.fillMaxWidth()
+                trailingIcon = {
+                    IconButton(onClick = { showAssignedDatePicker = true }) {
+                        Icon(Icons.Default.CalendarMonth, contentDescription = "Seleccionar fecha")
+                    }
+                },
+                modifier = Modifier.fillMaxWidth().clickable { showAssignedDatePicker = true }
             )
             
             Spacer(modifier = Modifier.height(16.dp))
             
             OutlinedTextField(
-                value = returnDate,
-                onValueChange = { returnDate = it },
+                value = returnDateDisplay,
+                onValueChange = {},
+                readOnly = true,
                 label = { Text(stringResource(R.string.label_return_date)) },
-                modifier = Modifier.fillMaxWidth()
+                trailingIcon = {
+                    IconButton(onClick = { showReturnDatePicker = true }) {
+                        Icon(Icons.Default.CalendarMonth, contentDescription = "Seleccionar fecha")
+                    }
+                },
+                modifier = Modifier.fillMaxWidth().clickable { showReturnDatePicker = true }
             )
             
             Spacer(modifier = Modifier.height(32.dp))
@@ -155,8 +244,8 @@ fun AddAssignmentScreen(
                                 Assignment(
                                     idSai = selectedSaiId!!,
                                     idPersona = selectedPersonId!!,
-                                    assignedDate = assignedDate.takeIf { it.isNotBlank() },
-                                    returnDate = returnDate.takeIf { it.isNotBlank() }
+                                    assignedDate = assignedDateDb.takeIf { it.isNotBlank() },
+                                    returnDate = returnDateDb.takeIf { it.isNotBlank() }
                                 )
                             ).onSuccess { 
                                 Toast.makeText(context, "Asignación guardada", Toast.LENGTH_SHORT).show()
diff --git a/app/src/main/java/com/example/saipp/ui/management/AddBatteryScreen.kt b/app/src/main/java/com/example/saipp/ui/management/AddBatteryScreen.kt
index 59fd26e..27528a7 100644
--- a/app/src/main/java/com/example/saipp/ui/management/AddBatteryScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/AddBatteryScreen.kt
@@ -1,9 +1,12 @@
 package com.example.saipp.ui.management
 
 import android.widget.Toast
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.*
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.CalendarMonth
+import androidx.compose.material.icons.filled.QrCodeScanner
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
@@ -15,7 +18,10 @@ import com.example.saipp.data.BatteryRepository
 import com.example.saipp.data.SaiRepository
 import com.example.saipp.data.model.Battery
 import com.example.saipp.data.model.Sai
+import com.example.saipp.ui.ScannerDialog
 import kotlinx.coroutines.launch
+import java.text.SimpleDateFormat
+import java.util.*
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -28,17 +34,64 @@ fun AddBatteryScreen(
     val saiRepository = remember { SaiRepository() }
     
     var brand by remember { mutableStateOf("") }
-    var installDate by remember { mutableStateOf("") }
+    var installDateDisplay by remember { mutableStateOf("") } // DD-MM-AAAA
+    var installDateDb by remember { mutableStateOf("") }      // YYYY-MM-DD
     var selectedSaiId by remember { mutableStateOf<Int?>(null) }
     
     var sais by remember { mutableStateOf<List<Sai>>(emptyList()) }
     var isSaving by remember { mutableStateOf(false) }
     var expanded by remember { mutableStateOf(false) }
+    var showDatePicker by remember { mutableStateOf(false) }
+    var showQuickScanner by remember { mutableStateOf(false) }
+
+    val datePickerState = rememberDatePickerState()
 
     LaunchedEffect(Unit) {
         saiRepository.getAll().onSuccess { sais = it }
     }
 
+    if (showDatePicker) {
+        DatePickerDialog(
+            onDismissRequest = { showDatePicker = false },
+            confirmButton = {
+                TextButton(onClick = {
+                    datePickerState.selectedDateMillis?.let { millis ->
+                        val date = Date(millis)
+                        val displayFormat = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault())
+                        val dbFormat = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
+                        installDateDisplay = displayFormat.format(date)
+                        installDateDb = dbFormat.format(date)
+                    }
+                    showDatePicker = false
+                }) {
+                    Text("Aceptar")
+                }
+            },
+            dismissButton = {
+                TextButton(onClick = { showDatePicker = false }) {
+                    Text("Cancelar")
+                }
+            }
+        ) {
+            DatePicker(state = datePickerState)
+        }
+    }
+
+    if (showQuickScanner) {
+        ScannerDialog(
+            onDismiss = { showQuickScanner = false },
+            onCodeScanned = { code ->
+                val matchingSai = sais.find { it.ns.equals(code, ignoreCase = true) }
+                if (matchingSai != null) {
+                    selectedSaiId = matchingSai.id
+                } else {
+                    Toast.makeText(context, "SAI no encontrado: $code", Toast.LENGTH_SHORT).show()
+                }
+                showQuickScanner = false
+            }
+        )
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
@@ -68,6 +121,14 @@ fun AddBatteryScreen(
                     onValueChange = {},
                     readOnly = true,
                     label = { Text(stringResource(R.string.label_sai)) },
+                    leadingIcon = {
+                        IconButton(onClick = { showQuickScanner = true }) {
+                            Icon(
+                                imageVector = Icons.Default.QrCodeScanner,
+                                contentDescription = "Escanear SAI"
+                            )
+                        }
+                    },
                     trailingIcon = { ExposedDropdownMenuDefaults.TrailingIcon(expanded = expanded) },
                     modifier = Modifier.menuAnchor().fillMaxWidth()
                 )
@@ -106,10 +167,18 @@ fun AddBatteryScreen(
             Spacer(modifier = Modifier.height(16.dp))
             
             OutlinedTextField(
-                value = installDate,
-                onValueChange = { installDate = it },
+                value = installDateDisplay,
+                onValueChange = {},
+                readOnly = true,
                 label = { Text(stringResource(R.string.label_install_date)) },
-                modifier = Modifier.fillMaxWidth()
+                trailingIcon = {
+                    IconButton(onClick = { showDatePicker = true }) {
+                        Icon(Icons.Default.CalendarMonth, contentDescription = "Seleccionar fecha")
+                    }
+                },
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .clickable { showDatePicker = true }
             )
             
             Spacer(modifier = Modifier.height(32.dp))
@@ -122,7 +191,7 @@ fun AddBatteryScreen(
                             Battery(
                                 idSai = selectedSaiId,
                                 brand = brand,
-                                installDate = installDate.takeIf { it.isNotBlank() }
+                                installDate = installDateDb.takeIf { it.isNotBlank() }
                             )
                         ).onSuccess { 
                             Toast.makeText(context, "Batería añadida", Toast.LENGTH_SHORT).show()
diff --git a/app/src/main/java/com/example/saipp/ui/management/AssignmentListScreen.kt b/app/src/main/java/com/example/saipp/ui/management/AssignmentListScreen.kt
index d6b7f3a..c93dc93 100644
--- a/app/src/main/java/com/example/saipp/ui/management/AssignmentListScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/AssignmentListScreen.kt
@@ -17,7 +17,11 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import com.example.saipp.data.AssignmentRepository
 import com.example.saipp.data.model.Assignment
+import com.example.saipp.ui.ScannerDialog
+import com.example.saipp.ui.SearchBar
 import kotlinx.coroutines.launch
+import java.text.SimpleDateFormat
+import java.util.*
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -31,6 +35,8 @@ fun AssignmentListScreen(
     val repository = remember { AssignmentRepository() }
     var items by remember { mutableStateOf<List<Assignment>>(emptyList()) }
     var isLoading by remember { mutableStateOf(true) }
+    var searchQuery by remember { mutableStateOf("") }
+    var showQuickScanner by remember { mutableStateOf(false) }
 
     fun loadItems() {
         scope.launch {
@@ -46,6 +52,25 @@ fun AssignmentListScreen(
         loadItems()
     }
 
+    val filteredItems = remember(items, searchQuery) {
+        items.filter { 
+            it.personName?.contains(searchQuery, ignoreCase = true) ?: false ||
+            it.saiNs?.contains(searchQuery, ignoreCase = true) ?: false
+        }
+    }
+
+    fun formatDate(dbDate: String?): String {
+        if (dbDate == null) return "N/A"
+        return try {
+            val dbFormat = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
+            val displayFormat = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault())
+            val date = dbFormat.parse(dbDate)
+            if (date != null) displayFormat.format(date) else dbDate
+        } catch (e: Exception) {
+            dbDate
+        }
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
@@ -63,44 +88,59 @@ fun AssignmentListScreen(
             }
         }
     ) { padding ->
-        if (isLoading) {
-            Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
-                CircularProgressIndicator()
+        Column(modifier = Modifier.fillMaxSize().padding(padding)) {
+            SearchBar(
+                query = searchQuery,
+                onQueryChange = { searchQuery = it },
+                onScanClick = { showQuickScanner = true },
+                modifier = Modifier.padding(16.dp)
+            )
+
+            if (showQuickScanner) {
+                ScannerDialog(
+                    onDismiss = { showQuickScanner = false },
+                    onCodeScanned = { code ->
+                        searchQuery = code
+                        showQuickScanner = false
+                    }
+                )
             }
-        } else {
-            LazyColumn(
-                modifier = Modifier
-                    .fillMaxSize()
-                    .padding(padding)
-            ) {
-                items(items) { item ->
-                    ListItem(
-                        headlineContent = { Text("${item.personName ?: "Persona desconocida"}") },
-                        supportingContent = { 
-                            Column {
-                                Text("SAI: ${item.saiNs ?: "N/A"}")
-                                Text("Asignado: ${item.assignedDate ?: "N/A"}")
-                                if (item.returnDate != null) {
-                                    Text("Devolución: ${item.returnDate}")
+
+            if (isLoading) {
+                Box(modifier = Modifier.weight(1f).fillMaxWidth(), contentAlignment = Alignment.Center) {
+                    CircularProgressIndicator()
+                }
+            } else {
+                LazyColumn(modifier = Modifier.weight(1f).fillMaxWidth()) {
+                    items(filteredItems) { item ->
+                        ListItem(
+                            headlineContent = { Text(item.personName ?: "Persona desconocida") },
+                            supportingContent = { 
+                                Column {
+                                    Text("SAI: ${item.saiNs ?: "N/A"}")
+                                    Text("Asignado: ${formatDate(item.assignedDate)}")
+                                    if (item.returnDate != null) {
+                                        Text("Devolución: ${formatDate(item.returnDate)}")
+                                    }
                                 }
-                            }
-                        },
-                        trailingContent = {
-                            Row {
-                                IconButton(onClick = { onNavigateToEdit(item.id) }) {
-                                    Icon(Icons.Default.Edit, contentDescription = "Editar")
-                                }
-                                IconButton(onClick = {
-                                    scope.launch {
-                                        repository.delete(item.id).onSuccess { loadItems() }
+                            },
+                            trailingContent = {
+                                Row {
+                                    IconButton(onClick = { onNavigateToEdit(item.id) }) {
+                                        Icon(Icons.Default.Edit, contentDescription = "Editar")
+                                    }
+                                    IconButton(onClick = {
+                                        scope.launch {
+                                            repository.delete(item.id).onSuccess { loadItems() }
+                                        }
+                                    }) {
+                                        Icon(Icons.Default.Delete, contentDescription = "Eliminar")
                                     }
-                                }) {
-                                    Icon(Icons.Default.Delete, contentDescription = "Eliminar")
                                 }
                             }
-                        }
-                    )
-                    HorizontalDivider()
+                        )
+                        HorizontalDivider()
+                    }
                 }
             }
         }
diff --git a/app/src/main/java/com/example/saipp/ui/management/BatteryListScreen.kt b/app/src/main/java/com/example/saipp/ui/management/BatteryListScreen.kt
index 63843ae..83a9f7b 100644
--- a/app/src/main/java/com/example/saipp/ui/management/BatteryListScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/BatteryListScreen.kt
@@ -17,7 +17,10 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import com.example.saipp.data.BatteryRepository
 import com.example.saipp.data.model.Battery
+import com.example.saipp.ui.SearchBar
 import kotlinx.coroutines.launch
+import java.text.SimpleDateFormat
+import java.util.*
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -31,6 +34,7 @@ fun BatteryListScreen(
     val repository = remember { BatteryRepository() }
     var items by remember { mutableStateOf<List<Battery>>(emptyList()) }
     var isLoading by remember { mutableStateOf(true) }
+    var searchQuery by remember { mutableStateOf("") }
 
     fun loadItems() {
         scope.launch {
@@ -46,6 +50,25 @@ fun BatteryListScreen(
         loadItems()
     }
 
+    val filteredItems = remember(items, searchQuery) {
+        items.filter { 
+            it.brand?.contains(searchQuery, ignoreCase = true) ?: false ||
+            it.idSai?.toString()?.contains(searchQuery) ?: false
+        }
+    }
+
+    fun formatDate(dbDate: String?): String {
+        if (dbDate == null) return "N/A"
+        return try {
+            val dbFormat = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
+            val displayFormat = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault())
+            val date = dbFormat.parse(dbDate)
+            if (date != null) displayFormat.format(date) else dbDate
+        } catch (e: Exception) {
+            dbDate
+        }
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
@@ -63,41 +86,45 @@ fun BatteryListScreen(
             }
         }
     ) { padding ->
-        if (isLoading) {
-            Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
-                CircularProgressIndicator()
-            }
-        } else {
-            LazyColumn(
-                modifier = Modifier
-                    .fillMaxSize()
-                    .padding(padding)
-            ) {
-                items(items) { item ->
-                    ListItem(
-                        headlineContent = { Text("Marca: ${item.brand ?: "Desconocida"}") },
-                        supportingContent = { 
-                            Column {
-                                Text("Instalación: ${item.installDate ?: "N/A"}")
-                                item.idSai?.let { Text("SAI ID: $it") }
-                            }
-                        },
-                        trailingContent = {
-                            Row {
-                                IconButton(onClick = { onNavigateToEdit(item.id) }) {
-                                    Icon(Icons.Default.Edit, contentDescription = "Editar")
+        Column(modifier = Modifier.fillMaxSize().padding(padding)) {
+            SearchBar(
+                query = searchQuery,
+                onQueryChange = { searchQuery = it },
+                modifier = Modifier.padding(16.dp)
+            )
+
+            if (isLoading) {
+                Box(modifier = Modifier.weight(1f).fillMaxWidth(), contentAlignment = Alignment.Center) {
+                    CircularProgressIndicator()
+                }
+            } else {
+                LazyColumn(modifier = Modifier.weight(1f).fillMaxWidth()) {
+                    items(filteredItems) { item ->
+                        ListItem(
+                            headlineContent = { Text("Marca: ${item.brand ?: "Desconocida"}") },
+                            supportingContent = { 
+                                Column {
+                                    Text("Instalación: ${formatDate(item.installDate)}")
+                                    item.idSai?.let { Text("SAI ID: $it") }
                                 }
-                                IconButton(onClick = {
-                                    scope.launch {
-                                        repository.delete(item.id).onSuccess { loadItems() }
+                            },
+                            trailingContent = {
+                                Row {
+                                    IconButton(onClick = { onNavigateToEdit(item.id) }) {
+                                        Icon(Icons.Default.Edit, contentDescription = "Editar")
+                                    }
+                                    IconButton(onClick = {
+                                        scope.launch {
+                                            repository.delete(item.id).onSuccess { loadItems() }
+                                        }
+                                    }) {
+                                        Icon(Icons.Default.Delete, contentDescription = "Eliminar")
                                     }
-                                }) {
-                                    Icon(Icons.Default.Delete, contentDescription = "Eliminar")
                                 }
                             }
-                        }
-                    )
-                    HorizontalDivider()
+                        )
+                        HorizontalDivider()
+                    }
                 }
             }
         }
diff --git a/app/src/main/java/com/example/saipp/ui/management/EditAssignmentScreen.kt b/app/src/main/java/com/example/saipp/ui/management/EditAssignmentScreen.kt
index e4594a3..4b6c700 100644
--- a/app/src/main/java/com/example/saipp/ui/management/EditAssignmentScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/EditAssignmentScreen.kt
@@ -1,9 +1,12 @@
 package com.example.saipp.ui.management
 
 import android.widget.Toast
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.*
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.CalendarMonth
+import androidx.compose.material.icons.filled.QrCodeScanner
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
@@ -17,7 +20,10 @@ import com.example.saipp.data.SaiRepository
 import com.example.saipp.data.model.Assignment
 import com.example.saipp.data.model.Person
 import com.example.saipp.data.model.Sai
+import com.example.saipp.ui.ScannerDialog
 import kotlinx.coroutines.launch
+import java.text.SimpleDateFormat
+import java.util.*
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -33,8 +39,11 @@ fun EditAssignmentScreen(
     
     var selectedSaiId by remember { mutableStateOf<Int?>(null) }
     var selectedPersonId by remember { mutableStateOf<Int?>(null) }
-    var assignedDate by remember { mutableStateOf("") }
-    var returnDate by remember { mutableStateOf("") }
+    
+    var assignedDateDisplay by remember { mutableStateOf("") }
+    var assignedDateDb by remember { mutableStateOf("") }
+    var returnDateDisplay by remember { mutableStateOf("") }
+    var returnDateDb by remember { mutableStateOf("") }
     
     var sais by remember { mutableStateOf<List<Sai>>(emptyList()) }
     var people by remember { mutableStateOf<List<Person>>(emptyList()) }
@@ -42,6 +51,13 @@ fun EditAssignmentScreen(
     var isSaving by remember { mutableStateOf(false) }
     var saiExpanded by remember { mutableStateOf(false) }
     var personExpanded by remember { mutableStateOf(false) }
+    
+    var showAssignedDatePicker by remember { mutableStateOf(false) }
+    var showReturnDatePicker by remember { mutableStateOf(false) }
+    var showQuickScanner by remember { mutableStateOf(false) }
+
+    val assignedDatePickerState = rememberDatePickerState()
+    val returnDatePickerState = rememberDatePickerState()
 
     LaunchedEffect(assignmentId) {
         val assignmentResult = repository.getById(assignmentId)
@@ -52,8 +68,32 @@ fun EditAssignmentScreen(
             val item = assignmentResult.getOrNull()!!
             selectedSaiId = item.idSai
             selectedPersonId = item.idPersona
-            assignedDate = item.assignedDate ?: ""
-            returnDate = item.returnDate ?: ""
+            
+            val dbFormat = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
+            val displayFormat = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault())
+            
+            item.assignedDate?.let { dateStr ->
+                try {
+                    val date = dbFormat.parse(dateStr)
+                    if (date != null) {
+                        assignedDateDisplay = displayFormat.format(date)
+                        assignedDateDb = dateStr
+                        assignedDatePickerState.selectedDateMillis = date.time
+                    }
+                } catch (e: Exception) {}
+            }
+            
+            item.returnDate?.let { dateStr ->
+                try {
+                    val date = dbFormat.parse(dateStr)
+                    if (date != null) {
+                        returnDateDisplay = displayFormat.format(date)
+                        returnDateDb = dateStr
+                        returnDatePickerState.selectedDateMillis = date.time
+                    }
+                } catch (e: Exception) {}
+            }
+
             sais = saisResult.getOrDefault(emptyList())
             people = peopleResult.getOrDefault(emptyList())
             isLoading = false
@@ -63,6 +103,59 @@ fun EditAssignmentScreen(
         }
     }
 
+    if (showAssignedDatePicker) {
+        DatePickerDialog(
+            onDismissRequest = { showAssignedDatePicker = false },
+            confirmButton = {
+                TextButton(onClick = {
+                    assignedDatePickerState.selectedDateMillis?.let { millis ->
+                        val date = Date(millis)
+                        assignedDateDisplay = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault()).format(date)
+                        assignedDateDb = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(date)
+                    }
+                    showAssignedDatePicker = false
+                }) { Text("Aceptar") }
+            },
+            dismissButton = {
+                TextButton(onClick = { showAssignedDatePicker = false }) { Text("Cancelar") }
+            }
+        ) { DatePicker(state = assignedDatePickerState) }
+    }
+
+    if (showReturnDatePicker) {
+        DatePickerDialog(
+            onDismissRequest = { showReturnDatePicker = false },
+            confirmButton = {
+                TextButton(onClick = {
+                    returnDatePickerState.selectedDateMillis?.let { millis ->
+                        val date = Date(millis)
+                        returnDateDisplay = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault()).format(date)
+                        returnDateDb = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(date)
+                    }
+                    showReturnDatePicker = false
+                }) { Text("Aceptar") }
+            },
+            dismissButton = {
+                TextButton(onClick = { showReturnDatePicker = false }) { Text("Cancelar") }
+            }
+        ) { DatePicker(state = returnDatePickerState) }
+    }
+
+    if (showQuickScanner) {
+        ScannerDialog(
+            onDismiss = { showQuickScanner = false },
+            onCodeScanned = { code ->
+                val matchingSai = sais.find { it.ns.equals(code, ignoreCase = true) }
+                if (matchingSai != null) {
+                    selectedSaiId = matchingSai.id
+                } else {
+                    Toast.makeText(context, "SAI no encontrado: $code", Toast.LENGTH_SHORT).show()
+                }
+                showQuickScanner = false
+            }
+        )
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
@@ -97,6 +190,14 @@ fun EditAssignmentScreen(
                         onValueChange = {},
                         readOnly = true,
                         label = { Text(stringResource(R.string.label_sai)) },
+                        leadingIcon = {
+                            IconButton(onClick = { showQuickScanner = true }) {
+                                Icon(
+                                    imageVector = Icons.Default.QrCodeScanner,
+                                    contentDescription = "Escanear SAI"
+                                )
+                            }
+                        },
                         trailingIcon = { ExposedDropdownMenuDefaults.TrailingIcon(expanded = saiExpanded) },
                         modifier = Modifier.menuAnchor().fillMaxWidth()
                     )
@@ -151,19 +252,31 @@ fun EditAssignmentScreen(
                 Spacer(modifier = Modifier.height(16.dp))
                 
                 OutlinedTextField(
-                    value = assignedDate,
-                    onValueChange = { assignedDate = it },
+                    value = assignedDateDisplay,
+                    onValueChange = {},
+                    readOnly = true,
                     label = { Text(stringResource(R.string.label_assigned_date)) },
-                    modifier = Modifier.fillMaxWidth()
+                    trailingIcon = {
+                        IconButton(onClick = { showAssignedDatePicker = true }) {
+                            Icon(Icons.Default.CalendarMonth, contentDescription = "Seleccionar fecha")
+                        }
+                    },
+                    modifier = Modifier.fillMaxWidth().clickable { showAssignedDatePicker = true }
                 )
                 
                 Spacer(modifier = Modifier.height(16.dp))
                 
                 OutlinedTextField(
-                    value = returnDate,
-                    onValueChange = { returnDate = it },
+                    value = returnDateDisplay,
+                    onValueChange = {},
+                    readOnly = true,
                     label = { Text(stringResource(R.string.label_return_date)) },
-                    modifier = Modifier.fillMaxWidth()
+                    trailingIcon = {
+                        IconButton(onClick = { showReturnDatePicker = true }) {
+                            Icon(Icons.Default.CalendarMonth, contentDescription = "Seleccionar fecha")
+                        }
+                    },
+                    modifier = Modifier.fillMaxWidth().clickable { showReturnDatePicker = true }
                 )
                 
                 Spacer(modifier = Modifier.height(32.dp))
@@ -178,8 +291,8 @@ fun EditAssignmentScreen(
                                         id = assignmentId,
                                         idSai = selectedSaiId!!,
                                         idPersona = selectedPersonId!!,
-                                        assignedDate = assignedDate.takeIf { it.isNotBlank() },
-                                        returnDate = returnDate.takeIf { it.isNotBlank() }
+                                        assignedDate = assignedDateDb.takeIf { it.isNotBlank() },
+                                        returnDate = returnDateDb.takeIf { it.isNotBlank() }
                                     )
                                 ).onSuccess { 
                                     Toast.makeText(context, "Asignación actualizada", Toast.LENGTH_SHORT).show()
diff --git a/app/src/main/java/com/example/saipp/ui/management/EditBatteryScreen.kt b/app/src/main/java/com/example/saipp/ui/management/EditBatteryScreen.kt
index 677215c..c05640f 100644
--- a/app/src/main/java/com/example/saipp/ui/management/EditBatteryScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/EditBatteryScreen.kt
@@ -1,9 +1,12 @@
 package com.example.saipp.ui.management
 
 import android.widget.Toast
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.*
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.CalendarMonth
+import androidx.compose.material.icons.filled.QrCodeScanner
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
@@ -15,7 +18,10 @@ import com.example.saipp.data.BatteryRepository
 import com.example.saipp.data.SaiRepository
 import com.example.saipp.data.model.Battery
 import com.example.saipp.data.model.Sai
+import com.example.saipp.ui.ScannerDialog
 import kotlinx.coroutines.launch
+import java.text.SimpleDateFormat
+import java.util.*
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -29,13 +35,18 @@ fun EditBatteryScreen(
     val saiRepository = remember { SaiRepository() }
     
     var brand by remember { mutableStateOf("") }
-    var installDate by remember { mutableStateOf("") }
+    var installDateDisplay by remember { mutableStateOf("") }
+    var installDateDb by remember { mutableStateOf("") }
     var selectedSaiId by remember { mutableStateOf<Int?>(null) }
     
     var sais by remember { mutableStateOf<List<Sai>>(emptyList()) }
     var isLoading by remember { mutableStateOf(true) }
     var isSaving by remember { mutableStateOf(false) }
     var expanded by remember { mutableStateOf(false) }
+    var showDatePicker by remember { mutableStateOf(false) }
+    var showQuickScanner by remember { mutableStateOf(false) }
+
+    val datePickerState = rememberDatePickerState()
 
     LaunchedEffect(batteryId) {
         val batteryResult = batteryRepository.getById(batteryId)
@@ -44,7 +55,24 @@ fun EditBatteryScreen(
         if (batteryResult.isSuccess) {
             val battery = batteryResult.getOrNull()!!
             brand = battery.brand ?: ""
-            installDate = battery.installDate ?: ""
+            
+            // Format existing date for display
+            battery.installDate?.let { dbDate ->
+                try {
+                    val dbFormat = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
+                    val displayFormat = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault())
+                    val date = dbFormat.parse(dbDate)
+                    if (date != null) {
+                        installDateDisplay = displayFormat.format(date)
+                        installDateDb = dbDate
+                        datePickerState.selectedDateMillis = date.time
+                    }
+                } catch (e: Exception) {
+                    installDateDisplay = dbDate
+                    installDateDb = dbDate
+                }
+            }
+            
             selectedSaiId = battery.idSai
             sais = saisResult.getOrDefault(emptyList())
             isLoading = false
@@ -54,6 +82,48 @@ fun EditBatteryScreen(
         }
     }
 
+    if (showDatePicker) {
+        DatePickerDialog(
+            onDismissRequest = { showDatePicker = false },
+            confirmButton = {
+                TextButton(onClick = {
+                    datePickerState.selectedDateMillis?.let { millis ->
+                        val date = Date(millis)
+                        val displayFormat = SimpleDateFormat("dd-MM-yyyy", Locale.getDefault())
+                        val dbFormat = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
+                        installDateDisplay = displayFormat.format(date)
+                        installDateDb = dbFormat.format(date)
+                    }
+                    showDatePicker = false
+                }) {
+                    Text("Aceptar")
+                }
+            },
+            dismissButton = {
+                TextButton(onClick = { showDatePicker = false }) {
+                    Text("Cancelar")
+                }
+            }
+        ) {
+            DatePicker(state = datePickerState)
+        }
+    }
+
+    if (showQuickScanner) {
+        ScannerDialog(
+            onDismiss = { showQuickScanner = false },
+            onCodeScanned = { code ->
+                val matchingSai = sais.find { it.ns.equals(code, ignoreCase = true) }
+                if (matchingSai != null) {
+                    selectedSaiId = matchingSai.id
+                } else {
+                    Toast.makeText(context, "SAI no encontrado: $code", Toast.LENGTH_SHORT).show()
+                }
+                showQuickScanner = false
+            }
+        )
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
@@ -88,6 +158,14 @@ fun EditBatteryScreen(
                         onValueChange = {},
                         readOnly = true,
                         label = { Text(stringResource(R.string.label_sai)) },
+                        leadingIcon = {
+                            IconButton(onClick = { showQuickScanner = true }) {
+                                Icon(
+                                    imageVector = Icons.Default.QrCodeScanner,
+                                    contentDescription = "Escanear SAI"
+                                )
+                            }
+                        },
                         trailingIcon = { ExposedDropdownMenuDefaults.TrailingIcon(expanded = expanded) },
                         modifier = Modifier.menuAnchor().fillMaxWidth()
                     )
@@ -126,10 +204,18 @@ fun EditBatteryScreen(
                 Spacer(modifier = Modifier.height(16.dp))
                 
                 OutlinedTextField(
-                    value = installDate,
-                    onValueChange = { installDate = it },
+                    value = installDateDisplay,
+                    onValueChange = {},
+                    readOnly = true,
                     label = { Text(stringResource(R.string.label_install_date)) },
-                    modifier = Modifier.fillMaxWidth()
+                    trailingIcon = {
+                        IconButton(onClick = { showDatePicker = true }) {
+                            Icon(Icons.Default.CalendarMonth, contentDescription = "Seleccionar fecha")
+                        }
+                    },
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .clickable { showDatePicker = true }
                 )
                 
                 Spacer(modifier = Modifier.height(32.dp))
@@ -143,7 +229,7 @@ fun EditBatteryScreen(
                                     id = batteryId,
                                     idSai = selectedSaiId,
                                     brand = brand,
-                                    installDate = installDate.takeIf { it.isNotBlank() }
+                                    installDate = installDateDb.takeIf { it.isNotBlank() }
                                 )
                             ).onSuccess { 
                                 Toast.makeText(context, "Batería actualizada", Toast.LENGTH_SHORT).show()
diff --git a/app/src/main/java/com/example/saipp/ui/management/EditSaiScreen.kt b/app/src/main/java/com/example/saipp/ui/management/EditSaiScreen.kt
index f4747e3..2f680d6 100644
--- a/app/src/main/java/com/example/saipp/ui/management/EditSaiScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/EditSaiScreen.kt
@@ -8,7 +8,9 @@ import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
+import com.example.saipp.R
 import com.example.saipp.data.SaiRepository
 import com.example.saipp.data.model.Sai
 import kotlinx.coroutines.launch
@@ -24,12 +26,14 @@ fun EditSaiScreen(
     val repository = remember { SaiRepository() }
     
     var ns by remember { mutableStateOf("") }
+    var modelo by remember { mutableStateOf("") }
     var isLoading by remember { mutableStateOf(true) }
     var isSaving by remember { mutableStateOf(false) }
 
     LaunchedEffect(saiId) {
         repository.getById(saiId).onSuccess {
             ns = it.ns
+            modelo = it.modelo ?: ""
             isLoading = false
         }.onFailure {
             Toast.makeText(context, "Error al cargar SAI", Toast.LENGTH_SHORT).show()
@@ -66,13 +70,20 @@ fun EditSaiScreen(
                     label = { Text("Número de Serie") },
                     modifier = Modifier.fillMaxWidth()
                 )
+                Spacer(modifier = Modifier.height(16.dp))
+                OutlinedTextField(
+                    value = modelo,
+                    onValueChange = { modelo = it },
+                    label = { Text(stringResource(R.string.label_modelo)) },
+                    modifier = Modifier.fillMaxWidth()
+                )
                 Spacer(modifier = Modifier.height(32.dp))
                 Button(
                     onClick = {
                         if (ns.isNotBlank()) {
                             isSaving = true
                             scope.launch {
-                                repository.update(Sai(id = saiId, ns = ns))
+                                repository.update(Sai(id = saiId, ns = ns, modelo = modelo))
                                     .onSuccess { 
                                         Toast.makeText(context, "SAI actualizado", Toast.LENGTH_SHORT).show()
                                         onNavigateBack()
diff --git a/app/src/main/java/com/example/saipp/ui/management/PersonListScreen.kt b/app/src/main/java/com/example/saipp/ui/management/PersonListScreen.kt
index 29d8025..1c2eca4 100644
--- a/app/src/main/java/com/example/saipp/ui/management/PersonListScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/PersonListScreen.kt
@@ -17,6 +17,7 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import com.example.saipp.data.PersonRepository
 import com.example.saipp.data.model.Person
+import com.example.saipp.ui.SearchBar
 import kotlinx.coroutines.launch
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -31,6 +32,7 @@ fun PersonListScreen(
     val repository = remember { PersonRepository() }
     var items by remember { mutableStateOf<List<Person>>(emptyList()) }
     var isLoading by remember { mutableStateOf(true) }
+    var searchQuery by remember { mutableStateOf("") }
 
     fun loadItems() {
         scope.launch {
@@ -46,6 +48,10 @@ fun PersonListScreen(
         loadItems()
     }
 
+    val filteredItems = remember(items, searchQuery) {
+        items.filter { it.name.contains(searchQuery, ignoreCase = true) }
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
@@ -63,35 +69,39 @@ fun PersonListScreen(
             }
         }
     ) { padding ->
-        if (isLoading) {
-            Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
-                CircularProgressIndicator()
-            }
-        } else {
-            LazyColumn(
-                modifier = Modifier
-                    .fillMaxSize()
-                    .padding(padding)
-            ) {
-                items(items) { item ->
-                    ListItem(
-                        headlineContent = { Text(item.name) },
-                        trailingContent = {
-                            Row {
-                                IconButton(onClick = { onNavigateToEdit(item.id) }) {
-                                    Icon(Icons.Default.Edit, contentDescription = "Editar")
-                                }
-                                IconButton(onClick = {
-                                    scope.launch {
-                                        repository.delete(item.id).onSuccess { loadItems() }
+        Column(modifier = Modifier.fillMaxSize().padding(padding)) {
+            SearchBar(
+                query = searchQuery,
+                onQueryChange = { searchQuery = it },
+                modifier = Modifier.padding(16.dp)
+            )
+
+            if (isLoading) {
+                Box(modifier = Modifier.weight(1f).fillMaxWidth(), contentAlignment = Alignment.Center) {
+                    CircularProgressIndicator()
+                }
+            } else {
+                LazyColumn(modifier = Modifier.weight(1f).fillMaxWidth()) {
+                    items(filteredItems) { item ->
+                        ListItem(
+                            headlineContent = { Text(item.name) },
+                            trailingContent = {
+                                Row {
+                                    IconButton(onClick = { onNavigateToEdit(item.id) }) {
+                                        Icon(Icons.Default.Edit, contentDescription = "Editar")
+                                    }
+                                    IconButton(onClick = {
+                                        scope.launch {
+                                            repository.delete(item.id).onSuccess { loadItems() }
+                                        }
+                                    }) {
+                                        Icon(Icons.Default.Delete, contentDescription = "Eliminar")
                                     }
-                                }) {
-                                    Icon(Icons.Default.Delete, contentDescription = "Eliminar")
                                 }
                             }
-                        }
-                    )
-                    HorizontalDivider()
+                        )
+                        HorizontalDivider()
+                    }
                 }
             }
         }
diff --git a/app/src/main/java/com/example/saipp/ui/management/SaiListScreen.kt b/app/src/main/java/com/example/saipp/ui/management/SaiListScreen.kt
index 2964a65..7cdb6c4 100644
--- a/app/src/main/java/com/example/saipp/ui/management/SaiListScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/SaiListScreen.kt
@@ -17,6 +17,8 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import com.example.saipp.data.SaiRepository
 import com.example.saipp.data.model.Sai
+import com.example.saipp.ui.ScannerDialog
+import com.example.saipp.ui.SearchBar
 import kotlinx.coroutines.launch
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -31,6 +33,8 @@ fun SaiListScreen(
     val repository = remember { SaiRepository() }
     var sais by remember { mutableStateOf<List<Sai>>(emptyList()) }
     var isLoading by remember { mutableStateOf(true) }
+    var searchQuery by remember { mutableStateOf("") }
+    var showQuickScanner by remember { mutableStateOf(false) }
 
     fun loadSais() {
         scope.launch {
@@ -46,6 +50,13 @@ fun SaiListScreen(
         loadSais()
     }
 
+    val filteredSais = remember(sais, searchQuery) {
+        sais.filter { 
+            it.ns.contains(searchQuery, ignoreCase = true) || 
+            (it.modelo?.contains(searchQuery, ignoreCase = true) ?: false)
+        }
+    }
+
     Scaffold(
         topBar = {
             TopAppBar(
@@ -63,35 +74,51 @@ fun SaiListScreen(
             }
         }
     ) { padding ->
-        if (isLoading) {
-            Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
-                CircularProgressIndicator()
+        Column(modifier = Modifier.fillMaxSize().padding(padding)) {
+            SearchBar(
+                query = searchQuery,
+                onQueryChange = { searchQuery = it },
+                modifier = Modifier.padding(16.dp),
+                onScanClick = { showQuickScanner = true }
+            )
+
+            if (showQuickScanner) {
+                ScannerDialog(
+                    onDismiss = { showQuickScanner = false },
+                    onCodeScanned = { code ->
+                        searchQuery = code
+                        showQuickScanner = false
+                    }
+                )
             }
-        } else {
-            LazyColumn(
-                modifier = Modifier
-                    .fillMaxSize()
-                    .padding(padding)
-            ) {
-                items(sais) { sai ->
-                    ListItem(
-                        headlineContent = { Text("NS: ${sai.ns}") },
-                        trailingContent = {
-                            Row {
-                                IconButton(onClick = { onNavigateToEdit(sai.id) }) {
-                                    Icon(Icons.Default.Edit, contentDescription = "Editar")
-                                }
-                                IconButton(onClick = {
-                                    scope.launch {
-                                        repository.delete(sai.id).onSuccess { loadSais() }
+
+            if (isLoading) {
+                Box(modifier = Modifier.weight(1f).fillMaxWidth(), contentAlignment = Alignment.Center) {
+                    CircularProgressIndicator()
+                }
+            } else {
+                LazyColumn(modifier = Modifier.weight(1f).fillMaxWidth()) {
+                    items(filteredSais) { sai ->
+                        ListItem(
+                            headlineContent = { Text("NS: ${sai.ns}") },
+                            supportingContent = { Text("Modelo: ${sai.modelo ?: "N/A"}") },
+                            trailingContent = {
+                                Row {
+                                    IconButton(onClick = { onNavigateToEdit(sai.id) }) {
+                                        Icon(Icons.Default.Edit, contentDescription = "Editar")
+                                    }
+                                    IconButton(onClick = {
+                                        scope.launch {
+                                            repository.delete(sai.id).onSuccess { loadSais() }
+                                        }
+                                    }) {
+                                        Icon(Icons.Default.Delete, contentDescription = "Eliminar")
                                     }
-                                }) {
-                                    Icon(Icons.Default.Delete, contentDescription = "Eliminar")
                                 }
                             }
-                        }
-                    )
-                    HorizontalDivider()
+                        )
+                        HorizontalDivider()
+                    }
                 }
             }
         }
diff --git a/app/src/main/java/com/example/saipp/ui/management/SaiScannerScreen.kt b/app/src/main/java/com/example/saipp/ui/management/SaiScannerScreen.kt
index cd8852c..7afe0c8 100644
--- a/app/src/main/java/com/example/saipp/ui/management/SaiScannerScreen.kt
+++ b/app/src/main/java/com/example/saipp/ui/management/SaiScannerScreen.kt
@@ -2,13 +2,10 @@ package com.example.saipp.ui.management
 
 import android.Manifest
 import android.content.pm.PackageManager
-import android.util.Log
 import android.widget.Toast
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.*
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.ArrowBack
 import androidx.compose.material3.*
@@ -16,9 +13,10 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import androidx.core.content.ContextCompat
-import com.example.saipp.ui.ResultDialog
+import com.example.saipp.R
 import com.example.saipp.data.SaiRepository
 import com.example.saipp.ui.scanner.BarcodeScannerView
 import kotlinx.coroutines.launch
@@ -55,6 +53,7 @@ fun SaiScannerScreen(
     }
 
     var scannedBarcode by remember { mutableStateOf<String?>(null) }
+    var modelo by remember { mutableStateOf("") }
     var isSaving by remember { mutableStateOf(false) }
 
     Scaffold(
@@ -91,20 +90,48 @@ fun SaiScannerScreen(
             }
 
             scannedBarcode?.let { barcode ->
-                ResultDialog(
-                    barcode = barcode,
-                    onDismiss = { scannedBarcode = null },
-                    onConfirm = {
-                        scannedBarcode = null
-                        isSaving = true
-                        scope.launch {
-                            repository.insert(barcode)
-                                .onSuccess { 
-                                    Toast.makeText(context, "SAI guardado", Toast.LENGTH_SHORT).show()
-                                    onNavigateBack()
+                AlertDialog(
+                    onDismissRequest = { scannedBarcode = null },
+                    title = { Text(text = stringResource(R.string.dialog_title)) },
+                    text = {
+                        Column {
+                            Text(text = "Código: $barcode")
+                            Spacer(modifier = Modifier.height(16.dp))
+                            OutlinedTextField(
+                                value = modelo,
+                                onValueChange = { modelo = it },
+                                label = { Text(stringResource(R.string.label_modelo)) },
+                                modifier = Modifier.fillMaxWidth()
+                            )
+                        }
+                    },
+                    confirmButton = {
+                        Button(onClick = {
+                            val codeToSave = scannedBarcode!!
+                            scannedBarcode = null
+                            isSaving = true
+                            scope.launch {
+                                // Check for duplicates
+                                val isRegisteredResult = repository.isNsRegistered(codeToSave)
+                                if (isRegisteredResult.getOrDefault(false)) {
+                                    Toast.makeText(context, R.string.error_duplicate_sai, Toast.LENGTH_LONG).show()
+                                } else {
+                                    repository.insert(codeToSave, modelo)
+                                        .onSuccess { 
+                                            Toast.makeText(context, "SAI guardado", Toast.LENGTH_SHORT).show()
+                                            onNavigateBack()
+                                        }
+                                        .onFailure { Toast.makeText(context, "Error: ${it.message}", Toast.LENGTH_SHORT).show() }
                                 }
-                                .onFailure { Toast.makeText(context, "Error: ${it.message}", Toast.LENGTH_SHORT).show() }
-                            isSaving = false
+                                isSaving = false
+                            }
+                        }) {
+                            Text(stringResource(R.string.button_save))
+                        }
+                    },
+                    dismissButton = {
+                        TextButton(onClick = { scannedBarcode = null }) {
+                            Text(stringResource(R.string.button_close))
                         }
                     }
                 )
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 8447b73..7ee2cc2 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -15,9 +15,13 @@
     <string name="no_rows_inserted">No se insertaron filas en la base de datos</string>
     <string name="label_sai">SAI</string>
     <string name="label_brand">Marca</string>
-    <string name="label_install_date">Fecha Instalación (AAAA-MM-DD HH:MM:SS)</string>
+    <string name="label_modelo">Modelo</string>
+    <string name="label_install_date">Fecha Instalación (DD-MM-AAAA)</string>
     <string name="select_sai">Seleccionar SAI</string>
     <string name="no_sai">Ninguno</string>
+    <string name="placeholder_search">Buscar...</string>
+    <string name="error_duplicate_sai">Este SAI ya está registrado en el sistema.</string>
+    <string name="scan_to_search">Escanear para buscar</string>
 
     <string name="menu_sais">Gestión de SAIs</string>
     <string name="menu_batteries">Gestión de Baterías</string>
@@ -25,7 +29,7 @@
     <string name="menu_assignments">Gestión de Asignaciones</string>
 
     <string name="label_person">Persona</string>
-    <string name="label_assigned_date">Fecha Asignación (AAAA-MM-DD)</string>
-    <string name="label_return_date">Fecha Devolución (AAAA-MM-DD)</string>
+    <string name="label_assigned_date">Fecha Asignación (DD-MM-AAAA)</string>
+    <string name="label_return_date">Fecha Devolución (DD-MM-AAAA)</string>
     <string name="select_person">Seleccionar Persona</string>
 </resources>
\ No newline at end of file