The Touch Sensor gives your robot a sense of touch. The Touch Sensor detects when it is being pressed by something and when it is released again.

Suggestions for use
You can use the touch Sensor to make your robot pick up things: a robotic arm equipped with a Touch Sensor lets the robot know whether or not there is something in its arm to grab. Or you can use a Touch Sensor to make your robot act on a command. For example, by pressing the Touch Sensor you can make your robot walk, talk, close a door, or turn on your TV.

Try Me
  The NXT comes with a Try Me function. Connect a Touch Sensor to port 1 of the NXT and select the Try Me submenu on the NXT to test your Touch Sensor. You’ll get a fun reaction.