Tekscan FlexiForce A201/1 Flex Sensor - 0-4.4N Force Range, 3-Pin Connector

The sensor acts as a variable resistor. You need a signal conditioning circuit, typically an inverting op-amp configuration. Connect the sensor's two active outer pins in series with a reference resistor (RF) between a negative excitation voltage (e.g., -5V) and the op-amp's inverting input. The op-amp's output will be a positive analog voltage proportional to the applied force, which can be read directly by your microcontroller's ADC pin. The center pin of the connector is inactive.

The reference resistor sets the sensitivity and force range of the measurement. A lower RF value (e.g., 10kΩ) will make the circuit less sensitive, allowing measurement of higher forces before the output saturates. A higher RF value (e.g., 1MΩ) increases sensitivity for detecting very low forces. Choose RF based on your expected force range and desired output voltage swing, typically between 10kΩ and 1MΩ. The drive voltage (VT) can also be adjusted to fine-tune the range.

Yes, the sensor length can be trimmed to predefined lengths of 2", 4", or 6". If you cut the sensor, you must attach a new connector to the freshly cut end. This requires purchasing compatible staked pin connectors and a crimping tool from Tekscan. Alternatively, you can use a conductive epoxy to solder small wires directly to the exposed silver traces on the trimmed end for permanent installation.

Force is only detected within the 9.53 mm diameter silver circle at the tip of the sensor. This is the 'active sensing area' where the pressure-sensitive ink is located. The long tail of the sensor contains only the conductive silver traces that connect this area to the pins. Applying force to the tail will not produce a meaningful resistance change. Ensure your mounting applies force directly and evenly over the circular silver pad.