New Touch Sensors

Overview:

Touch sensitive devices have become increasingly common – from cell phones to industrial touch panels to appliances. These devices typically use capacitive sensors to create the 'touch' surface. In reality capacitive does not require touch, but merely close proximity of an object capable of changing the capacitance of the system. Capacitive systems are typically limited to non-metallic materials, may not work well with gloves and can be susceptible to false activations caused by water. Even with these limitation capacitive works well for many consumer applications.
For situations with more stringent requirements – requiring a definitive touch, wet/underwater applications or high vandalism potential – another technology is possible. Trapped Acoustic Resonance technology expands touch-sensitive capabilities into metallic substrates. The technology, referred to simply as ActiveTouch, was developed by ITW (Illinois Tools Works) over the past seven years, and can turn a solid steel plate up to 0.5" thick into a touch sensitive surface with multiple switch points. The technology even works with ballistic steel, creating the potential for putting a switch in a bullet proof steel plate with no seams.