Capacitive switches have become increasingly common. Even if you’re unfamiliar with the technology itself, you’ve probably used a capacitive switch. They are found in dozens of everyday electrical devices, including appliances, remote controls, infotainment systems and more. While capacitive switches provide the same circuit-controlling mechanisms as other switches, they operate in a unique way. To learn more about capacitive switches and the benefits they offer, keep reading.

What Is a Capacitive Switch?

A capacitive switch is an electrical component that’s designed to control a circuit. It’s different from other switches, however, in the sense that it uses capacitance to determine when to open and close the circuit. Capacitive switches emit an electrostatic field while simultaneously measuring the charge. If the charge changes, the capacitive switch will change the orientation of the circuit by opening or closing it.

Capacitive switches aren’t much different from capacitive touchscreens. They both emit a uniform electrostatic field, and they both measure the charge of this field. Touching a capacitive switch will add a small amount of electricity to its electrostatic field. In turn, the capacitive switch will identify your command, and it will respond by opening or closing the circuit.

Most capacitive switches feature the following parts:

  • Graphic overlay layer
  • Circuit
  • Backer

It’s important to note that the circuit may consist of either a Flexible Printed Circuit (FPC) or a Printed Circuit Board (PCB). FPCs live up to their namesake by featuring a circuit on a flexible substrate.

Benefits of Capacitive Switches

Capacitive switches aren’t the same as mechanical switches. Mechanical switches feature moving and mechanical parts, which are used to open and close a circuit. Capacitive switches don’t have moving parts. Instead, they operate on the principle of capacitance. Touching the capacitive switch’s button will change its electrostatic field. As a result, the capacitive switch can open and close the circuit without stressing its internal components. The end result is a longer-lasting switching solution.

Another benefit of capacitive switches is that they support backlighting. If you’re planning to use it in a dark or otherwise poorly lit environment, you need backlighting to illuminate the switch’s buttons. Fortunately, capacitive switches support several backlighting options. They can be designed with electroluminescent (EL) or light-emitting diode (LED) backlighting.

Finally, capacitive switches are incredibly durable. They can withstand otherwise harsh environments that would cause other types of switches, such as mechanical switches, to fail. For these reasons, capacitive switches are on the rise.