How Capacitive Sensors Work

Materials

Xymox - Sensor & Display
Xymox - PCAP Sensor

The sensor itself is an electrical capacitor, and the controller measures the capacitance of the sensor.  When your finger (or anything that holds an electrical charge) approaches and touches the sensor, the capacitance of the sensor changes.  The “partnership” between the sensor and the controller is critical, so that the controller knows how to interpret a change in capacitance.  This requires a match between the electrical conductivity of the sensor material, the efficiency of the electrical traces that connect the sensor to the controller, and the controller itself.

One of the fantastic aspects of Xymox’s process for making capacitive sensors is that we can tailor the exact sensor pattern to your needs – if you need discrete touch points, that’s what we make. If you need a slider, we make that just for you.  If you need a full touch, high definition sensor, that’s what we make for you.

At the heart of a touch sensor is a material that is clear and at the same time electrically conductive. At Xymox we use a material called PEDOT – a very flexible polymer that adheres very well to polyester base films.

Transparent Sensors

  • Used over displays
  • Full matrix multi-touch sensors and discrete button sensors
  • Kodak HCF - Kodak’s expertise in film technology means they coat PEDOT perfectly onto super-clear polyester.  Then Xymox processes that HCF (Highly Conductive Film) into a custom touch sensor.

Translucent Sensors

  • Used mainly in backlighting applications
  • Discrete button patterns for either self-capacitive or mutual-capacitive designs

Using state of the art technology and conductive silver ink made in house, Xymox can produce parts with 200 micron line weights.

 

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