Membrane switches are used in countless electronic devices. Among other things, you can find them in TV remotes, air conditioners, microwaves, human machine interfaces (HMIs) and more. Featuring a low profile and flexible construction, they offer an attractive alternative to mechanical switches. In this post,
What Is a Membrane Switch?
The American Society for Testing and Materials (ASTM) defines the term “membrane switch” as being an electrical switch featuring at least one flexible contact. This is in stark contrast to mechanical switches, which feature rigid contacts. Some membrane switches have multiple flexible contacts, but they are all characterized by the use of at least one flexible contact.
How Membrane Switches Are Constructed
Membrane switches are constructed of multiple laminated layers. While the exact construction of a membrane switch can vary depending on its intended application, most feature a membrane overlay layer, a spacer, a printed circuit, adhesive and tail filler.
While mechanical switches are typically made of copper and plastic components, membrane switches are made of printed circuits. The ink used in the printed circuits consists of copper, silver or graphite. As a result, it’s able to conduct electricity. When you press a button or key on a membrane switch, the two contacts will meet, thereby completing the circuit. With membrane switches, at least one of the contacts are made of a flexible material.
Why Membrane Switches Are a Popular Alternative to Mechanical Switches
In recent years, membrane switches have become an increasingly popular alternative to mechanical switches — and for good reason. With their flexible construction, membrane switches can be used small and compact devices that aren’t able to accommodate the larger and more rigid mechanical switches.
Furthermore, membrane switches offer better resistance to moisture than mechanical switches. This allows membrane switches to be used in otherwise harsh environments, including the outdoors, without succumbing to damage.
Backlighting can also be used in membrane switches to illuminate keys and buttons. Light-emitting diode (LED) bulbs, for example, can be installed — either alone or in conjunction with light guides — for backlighting in a membrane switch.
Membrane switches are used in countless industries, ranging from medical and retail to aerospace and automotive. When compared to mechanical switches, they offer an attractive choice for companies in need of a switching solution. Membrane switches can be used in small electrical devices, offer greater resistance to moisture, and they support backlighting.