Interlink Electronics FSR UX 400 Short Tail Membrane Pressure Sensor - 7.6mm Round - Soldertabs

This sensor is able to measure pressure using the membranes that are incorporated in the sensor. The resistance of the sensor changes based on the pressure on the membrane. You can easily read the sensor on an analog input pin of a microcontroller with a simple voltage divider.

See the following page to get the sensor working with Arduino: How to use a Force Sensitive Resistor - Arduino Tutorial.

Note: The pins of this sensor are difficult to solder because of the plastic that can melt. We recommend only soldering the sensor if you have enough soldering experience.