Tekscan FlexiForce A201 Variable Resistance Sensors
The FlexiForce A201 variable resistance sensors can be used with Biometrics DataLINK and DataLOG systems, Thought's ProComp2, ProComp Infiniti and FlexComp Infiniti systems, as well as customer data acquisition systems.
The FlexiForce A201 force sensor is an ultra-thin, flexible printed circuit. The force sensors are constructed of two layers of substrate (polyester/polyimide) film. On each layer, a conductive material (silver) is applied, followed by a layer of pressure-sensitive ink. Adhesive is then used to laminate the two layers of substrate together to form the force sensor. The active sensing area is defined by the silver circle on top of the pressure-sensitive ink. Silver extends from the sensing area to the connectors at the other end of the sensor, forming the conductive leads. A201 sensors are terminated with male square pins, allowing them to be easily incorporated into a circuit. The two outer pins of the connector are active and the center pin is inactive.
8" A201 Sensor
The FlexiForce single element force sensor acts as a force sensing resistor in an electrical circuit. When the force sensor is unloaded, its resistance is very high. When a force is applied to the sensor, this resistance decreases. The resistance can be read by connecting a multimeter to the outer two pins, then applying a force to the sensing area. In the image below, the plot shows both the Force vs. resistance and Force vs. conductance (1/R). Note that the conductance curve is linear, and therefore useful in calibration.
|One way to integrate the A201 force sensor into an application is to incorporate it into a force-to-voltage circuit. A means of calibration must then be established to convert the output into the appropriate engineering units. Depending on the setup, an adjustment could then be done to increase or decrease the sensitivity of the force sensor. The chart to the right shows a typical sensor response (based on our recommended drive circuit shown below).
Specifications & Features
||0.375" diameter (9.53mm)
||3-pin male square pin
||< ±2.5% of full scale (conditioned sensor, 80% force applied)
||< 4.5% of full scale (conditioned sensor, 80% force applied)
||< 5% per logarithmic time scale (constant load of 90% sensor rating)
||< 5 microseconds
||15°F - 140°F (-9°C - 60°C)
||0-1 lb. (4.4 N)
0-25 lbs. (110 N)
0-100 lbs. (440 N)*
||Output variance up to 0.2% per degree F (approx. 0.36% per degree C)
* See recommended drive circuit below. In order to measure forces above 100 lbs. (up to 1000 lbs.), apply a lower drive voltage and reduce the resistance of the feedback resistor (1 kΩ min).
Example of a FlexiForce Excitation Circuit
FlexiForce Female Berg Receptacle
The female berg connector is an optional component that easily connects A201 sensors (which have a male pin termination) to discrete wires or another flexcircuit.
FlexiForce Male Berg Connector
The male berg connector is an optional component that can be easily crimped to an A201 sensor that has been trimmed in length.
FlexiForce Quickstart Board
The FlexiForce Quickstart Board is a finished single voltage source circuit which can be quickly dropped into a prototype or easily designed into a product to obtain force measurements.
It is designed for easy integration of FlexiForce sensors. It provides a 0-5V analog voltage output that can be used as an input on your microcontroller or third-party data acquisition system. The Quickstart Board contains:
- (1) FlexiForce Quickstart Board
- Dimensions: 1.25" x 1.25"
- Input: 3.3V - 9V
- Output: 0V - 5V nominal (Vin ≥ 5V)
- (1) battery clip
- (2) FlexiForce A201 sensors
- Signal conditioning that allows the ability to adjust or modify dynamic range
- Eliminates time developing circuits
- Perfect for a plug and play product to drop into a design
||0-1 lb Flexiforce series sensors 4-pack
||0-1 lb Flexiforce series sensors 8-pack
||0-25 lb Flexiforce series sensors 4-pack
||0-25 lb Flexiforce series sensors 8-pack
||0-100 lb Flexiforce series sensors 4-pack
||0-100 lb Flexiforce series sensors 8-pack
||FlexiForce Female Berg Receptacle
||FlexiForce Male Berg Connector
||FlexiForce Quickstart Board
A201 sensors can also be ordered in 2", 4", and 6" lengths for an additional fee.
FlexiForce is a trademark of Tekscan, Inc.