diff --git a/CMakeLists.txt b/CMakeLists.txt
index 258d06c..da4e226 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,6 +10,7 @@ include_directories(${CUDAToolkit_INCLUDE_DIRS})
 # Add project source files for the library
 set(LIBRARY_SOURCES
     src/utils/cuda_helper.cu
+    src/functions/activations.cu
     src/layers/dense.cu
 )
 
@@ -27,11 +28,12 @@ target_link_libraries(${PROJECT_NAME} CUDA::cublas CUDA::cudart)
 target_include_directories(${PROJECT_NAME} PUBLIC
     ${CMAKE_CURRENT_SOURCE_DIR}/include
     ${CMAKE_CURRENT_SOURCE_DIR}/include/utils
+    ${CMAKE_CURRENT_SOURCE_DIR}/include/functions
     ${CMAKE_CURRENT_SOURCE_DIR}/include/layers
     ${CMAKE_CURRENT_SOURCE_DIR}/src
 )
 
-set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 14)
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 20)
 
 # Add testing subdirectory
 add_subdirectory(test)
\ No newline at end of file
diff --git a/include/functions/activations.cuh b/include/functions/activations.cuh
new file mode 100644
index 0000000..638756c
--- /dev/null
+++ b/include/functions/activations.cuh
@@ -0,0 +1,14 @@
+#include <functional>
+
+#ifndef ACTIVATIONS_H
+#define ACTIVATIONS_H
+
+__device__ float sigmoid(float a);
+__device__ float relu(float a);
+__device__ float linear(float a);
+
+__global__ void sigmoid_kernel(const float* __restrict__ src, float* __restrict__ dst, int len);
+__global__ void relu_kernel(const float* __restrict__ src, float* __restrict__ dst, int len);
+__global__ void linear_kernel(const float* __restrict__ src, float* __restrict__ dst, int len);
+
+#endif // ACTIVATIONS_H
\ No newline at end of file
diff --git a/include/layers/conv.cuh b/include/layers/conv.cuh
index 63c5ccc..eed7d76 100644
--- a/include/layers/conv.cuh
+++ b/include/layers/conv.cuh
@@ -1,5 +1,3 @@
-// fully_connected_layer.h
-
 #ifndef CONV_LAYER_H
 #define CONV_LAYER_H
 
diff --git a/include/layers/dense.cuh b/include/layers/dense.cuh
index cd002fd..9393154 100644
--- a/include/layers/dense.cuh
+++ b/include/layers/dense.cuh
@@ -1,15 +1,17 @@
 #ifndef DENSE_LAYER_H
 #define DENSE_LAYER_H
 
+#include <functional>
 #include <vector>
 #include <cublas_v2.h>
-#include <ilayer.cuh>
+#include <string>
+#include "ilayer.cuh"
 
 namespace Layers {
 
     class Dense : public ILayer {
     public:
-        Dense(int inputSize, int outputSize, cublasHandle_t cublasHandle);
+        Dense(int inputSize, int outputSize, std::string activation, cublasHandle_t cublasHandle);
         ~Dense();
 
         void forward(const float* input, float* output);
@@ -28,6 +30,8 @@ namespace Layers {
         std::vector<float> weights;
         std::vector<float> biases;
 
+        std::string activation;
+
         void initializeWeights();
         void initializeBiases();
         void toCuda();
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
deleted file mode 100644
index bbf5f52..0000000
--- a/src/CMakeLists.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-set(LAYER_SOURCES layers/dense.cu)
-
-add_library(CUDANet
-    utils/cuda_helper.cu
-    utils/functions.cu
-    ${LAYER_SOURCES}
-)
diff --git a/src/functions/activations.cu b/src/functions/activations.cu
new file mode 100644
index 0000000..57399b4
--- /dev/null
+++ b/src/functions/activations.cu
@@ -0,0 +1,44 @@
+#include "activations.cuh"
+#include <functional>
+
+__device__ float sigmoid(float a)
+{
+    return 1.0 / (1.0 + exp (-a));
+}
+
+__device__ float relu(float a)
+{
+    return a < 0.0 ? 0.0 : a;
+}
+
+__device__ float linear(float a)
+{
+    return a;
+}
+
+__global__ void sigmoid_kernel(const float* __restrict__ src, float* __restrict__ dst, int len) {
+  int stride = gridDim.x * blockDim.x;
+  int tid = blockDim.x * blockIdx.x + threadIdx.x;
+
+  for (int i = tid; i < len; i += stride) {
+    dst[i] = sigmoid(src[i]);
+  }
+}
+
+__global__ void relu_kernel(const float* __restrict__ src, float* __restrict__ dst, int len) {
+  int stride = gridDim.x * blockDim.x;
+  int tid = blockDim.x * blockIdx.x + threadIdx.x;
+
+  for (int i = tid; i < len; i += stride) {
+    dst[i] = relu(src[i]);
+  }
+}
+
+__global__ void linear_kernel(const float* __restrict__ src, float* __restrict__ dst, int len) {
+  int stride = gridDim.x * blockDim.x;
+  int tid = blockDim.x * blockIdx.x + threadIdx.x;
+
+  for (int i = tid; i < len; i += stride) {
+    dst[i] = linear(src[i]);
+  }
+}
diff --git a/src/layers/dense.cu b/src/layers/dense.cu
index 86f3328..37b6dc3 100644
--- a/src/layers/dense.cu
+++ b/src/layers/dense.cu
@@ -1,13 +1,15 @@
 #include "dense.cuh"
 #include "cuda_helper.cuh"
+#include "activations.cuh"
 #include <cstdlib>
 #include <cuda_runtime.h>
 #include <cublas_v2.h>
 #include <cstdio>
 #include <iostream>
+#include <functional>
 
-Layers::Dense::Dense(int inputSize, int outputSize, cublasHandle_t cublasHandle)
-    : inputSize(inputSize), outputSize(outputSize), cublasHandle(cublasHandle) {
+Layers::Dense::Dense(int inputSize, int outputSize, std::string activation, cublasHandle_t cublasHandle)
+    : inputSize(inputSize), outputSize(outputSize), cublasHandle(cublasHandle), activation(activation) {
 
     // Allocate memory for weights and biases
     weights.resize(outputSize * inputSize);
@@ -33,13 +35,7 @@ Layers::Dense::~Dense() {
 }
 
 void Layers::Dense::initializeWeights() {
-
-    for (int j = 0; j < inputSize; ++j) {
-        for (int i = 0; i < outputSize; ++i) {
-            int idx = IDX2C(i, j, outputSize);
-            weights[idx] = 0.0f;
-        }
-    }
+    std::fill(weights.begin(), weights.end(), 0.0f);
 }
 
 void Layers::Dense::initializeBiases() {
@@ -52,6 +48,18 @@ void Layers::Dense::forward(const float* d_input, float* d_output) {
 
     CUBLAS_CHECK(cublasSgemv(cublasHandle, CUBLAS_OP_N, inputSize, outputSize, &alpha, d_weights, inputSize, d_input, 1, &beta, d_output, 1));
     CUBLAS_CHECK(cublasSaxpy(cublasHandle, outputSize, &alpha, d_biases, 1, d_output, 1));
+
+    int threadsPerBlock = 256;
+    int blocksPerGrid = (outputSize + threadsPerBlock - 1) / threadsPerBlock;
+
+    if (activation == "sigmoid") {
+        sigmoid_kernel<<<blocksPerGrid, threadsPerBlock>>>(d_output, d_output, outputSize);
+    } else if (activation == "relu") {
+        relu_kernel<<<blocksPerGrid, threadsPerBlock>>>(d_output, d_output, outputSize);
+    } else {
+        linear_kernel<<<blocksPerGrid, threadsPerBlock>>>(d_output, d_output, outputSize);
+    }
+
 }
 
 void Layers::Dense::toCuda() {
diff --git a/test/layers/test_dense.cu b/test/layers/test_dense.cu
index 226d03b..cecd1ad 100644
--- a/test/layers/test_dense.cu
+++ b/test/layers/test_dense.cu
@@ -2,6 +2,7 @@
 #include <cuda_runtime_api.h>
 #include <driver_types.h>
 #include <iostream>
+#include "activations.cuh"
 #include "dense.cuh"
 #include "test_cublas_fixture.cuh"
 
@@ -9,7 +10,7 @@ class DenseLayerTest : public CublasTestFixture {
 protected:
     Layers::Dense commonTestSetup(int inputSize, int outputSize, std::vector<float>& input, std::vector<std::vector<float>>& weights, std::vector<float>& biases, float*& d_input, float*& d_output) {
         // Create Dense layer
-        Layers::Dense denseLayer(inputSize, outputSize, cublasHandle);
+        Layers::Dense denseLayer(inputSize, outputSize, "linear", cublasHandle);
 
         // Set weights and biases
         denseLayer.setWeights(weights);
@@ -48,7 +49,7 @@ TEST_F(DenseLayerTest, Init) {
             int outputSize = j;
 
             // std::cout << "Dense layer: input size = " << inputSize << ", output size = " << outputSize << std::endl;
-            Layers::Dense denseLayer(inputSize, outputSize, cublasHandle);
+            Layers::Dense denseLayer(inputSize, outputSize, "linear", cublasHandle);
         }    
     }
 }
@@ -67,7 +68,7 @@ TEST_F(DenseLayerTest, setWeights) {
         {1.3f, 0.5f, 0.0f, 1.7f}
     };
 
-    Layers::Dense denseLayer(inputSize, outputSize, cublasHandle);
+    Layers::Dense denseLayer(inputSize, outputSize, "linear", cublasHandle);
 
     denseLayer.setWeights(weights);
 
diff --git a/test/utils/test_functions.cu b/test/utils/test_functions.cu
new file mode 100644
index 0000000..8431916
--- /dev/null
+++ b/test/utils/test_functions.cu
@@ -0,0 +1,16 @@
+#include "gtest/gtest.h"
+#include <cuda_runtime_api.h>
+#include <driver_types.h>
+#include <iostream>
+#include "functions.cuh"
+#include "test_cublas_fixture.cuh"
+
+class FunctionsTest : public CublasTestFixture {
+protected:
+    cudaError_t cudaStatus;
+    cublasStatus_t cublasStatus;
+};
+
+TEST_F(FunctionsTest, sigmoid) {
+
+}
\ No newline at end of file