Capacitive Touch Sensor (TTP223-B)

From the shop's description

The touching detection is designed for replacing traditional direct button key. The sensor is essentially a button style sensor that detects when it is being pressed. One of the main differences is that it detects the presence of your finger on the sensor. This means that it doesn’t require any force to activate the button. You can place the metallic pad under a non-metallic surface such as a plastic or glass sheet and it will still work as a button, which is useful for projects that have to be waterproof. With the help of the touch sensor, you can also make a secret button. Working principle of capacitive touch sensor Capacitive touch sensor contains two parallel conductors with an insulator between them. These conductor plates act as a capacitor with specific capacitance value. When these conductor plates come in contact with our fingers, our finger acts as a conductive object and it will change the capacitance value at the position of touching. Features 2V to 5.5V Supply Capacitive touch sensor tutorial