Force sensing resistive touch sensor

Force sensing touch (FST) sensors provide extra functionality compared to existing touch
sensors based on capacitive sensing. They enable a new type of gesturing – the ability for
electronic devices to recognize the location and amount of force or pressure of a touch point.
This can be used in track-pads, keyboards, touch screens, game controllers and the like. They
enhance the user’s ability to interact with an electronic device or computer and for the
manufacturer they can really differentiate their product in the marketplace. The problem is
that existing FST sensors have poor uniformity of response, give false triggering, have poor
mechanical robustness and need too large a first touch activation force. Our concept is to
eliminate these problems by using a novel type of flexible circuit board in the construction of
the sensor. This board will enable us to make resistive FST sensors without any spacer
structures or air gaps and with much lower resistance of the individual sensor drive lines in
the matrix pattern. Our sensor will have the additional benefits of being free from electrical
interference and will draw less power, as no current flows until the sensor is touched.