A capacitive switch is an electronic capacitor that measures changes in capacitance values when a conductive object such as your finger moves closer to the sensing area. The change in that value is interpreted and registers that change as an activation of the switch. A capacitive switch can be either a flexible printed circuit or a sensing pad on a rigid PCB. A capacitive switch can incorporate a lot of functionality that is not easily attained with a normal membrane or mechanical switch. Capacitive switches can have intensity sliders, sensitive areas in multiple shapes such as a circle, and can have varying levels of sensitivity for activation. You also can have options like a proximity sensor incorporated into a capacitive switch for additional functional benefits. As a capacitive switch is a sensor that senses through a non-conductive surface, thicker substrates can be used such as safety glass, or acrylic materials for a very robust switch. This can also give the ability for additional gasketing for harsh environments. It is also possible to achieve very intricate backlighting solutions with capacitive switch technologies.
