Membrane switches have become an increasingly popular alternative to mechanical switches. You can now find them used in a variety of industries, including medical, aerospace, defense, consumer, industrial and even video gaming. But if you’re thinking about purchasing a new switch, you might be wondering whether they are a smart choice.
The Basics of Membrane Switches
A membrane switch is an electrical switch that’s characterized by a flexible design. Like all electrical switches, it’s used to turn on and off a circuit. When you press a button on an electrical switch, the circuit is complete. When you release the button, the circuit reverts back to its default open position. Only membrane switches, however, are made of a flexible substrate. And while that may sound like a subtle nuance, it yields several key benefits.
The Benefits of Membrane Switches
So, why should you consider using a membrane switch instead of a mechanical switch? Mechanical switches offer little or no protection against moisture damage. When used outdoors — or other environments where water is a concern — moisture may penetrate past the keys and into the switch’s underlying circuitry. Of course, the ingress of water can permanently damage a switch’s circuitry, but this typically isn’t a problem with membrane switches.
Membrane switches are generally sealed to protect against moisture and liquids. The flexible surface allows for an impermeable membrane that prevents water, oil or other liquids from reaching the underlying circuitry. As a result, membrane switches can be used in environments where mechanical switches cannot be used.
Backlighting for Membrane Switches
Membrane switches are often used with backlighting to illuminate the keys and legends used on their buttons. There are three primary backlighting methods used in membrane switches: light-emitting diode (LED), optical fiber and electroluminescent (EL). With that said, LED backlighting is typically used for indicator lights rather than as a complete backlighting solution.
For a complete backlighting solution, either optical fiber or EL is used. Optical fiber is particularly useful because it’s able to last for up to 100,000 hours. Furthermore, it’s not susceptible to degradation caused by extreme temperatures or extreme humidity levels.
In conclusion, membrane switches are electrical switches with a flexible substrate. They offer a higher level of resistance to water and liquids than mechanical switches, making them a popular choice for businesses. And when used with the right backlighting solution, membrane switches can provide a superior level of visibility and clarity.