Force sensor (round)
The FSR 402 is a single-zone Force Sensing Resistor® optimized for use in human touch control of electronic devices such as automotive electronics, medical systems, and in industrial and robotics applications, among many others. FSRs are two-wire, robust polymer thick film (PTF) sensors that exhibit a decrease in resistance with an increase in force applied to the surface of the sensor. Its active area is 12.7 mm diameter, and the sensor is available with four connection options.
RA12P- https://botland.store/pressure-sensors/12153-force-sensor-ra12p-4kg-round-12-mm.html
MFSR-R18-1B- https://botland.store/pressure-sensors/12156-force-sensor-ra18-diy-4kg-round-18mm-5904422318772.html
34-00065- https://www.digikey.ca/en/products/detail/interlink-electronics/34-00065/7672219
RP-C18.3-ST- https://www.dfrobot.com/product-1844.html