A401 FlexiForce™ Piezoresistive Force Sensor Tekscan A401 FlexiForce™ Piezoresistive Force Sensor offers a large ø25.4mm (2.24') sensing area and measures up to 31,138N (7,000lbs.). The thin, flexible sensor is available off-the-shelf for easy proof of concept and in large volumes for design-in applications. To measure higher forces, apply a lower drive voltage (VT) or reduce the resistance of the feedback resistor (RF). Conversely, the sensitivity can be increased for the measurement of lower forces by increasing VT or RF.