A force sensor, or force sensitive resistor is a variable resistor in which its resistance varies with the amount of pressure placed on it.
When pressure is applied to the force sensor, resistance changes inversely with the force applied, i.e., an increase in pressure applied causes a decrease in resistance and an increase in conductivity, while releasing the applied pressure cause the resistance to return to its native state.
There are various configurations that can be used to make a force sensing resistor, and they all use a special silver based ink and a conductive carbon ink printed on PET separated by a spacer.
When pressure is applied to active area of the force sensing resistor assembly, silver based and conductive carbon inks make contact and complete the circuit. A special ink system is used to achieve the desired resistance values on the force sensor pads.
