Membrane Switch vs Mechanical Switch: What’s the Difference?

Membrane switches are used in variety of applications, some of which include microwaves, air conditioners, remote controls and human machine interfaces (HMI).  Like all switches, its primary purpose is to control the flow of electricity in a circuit. When the switch is open, electricity can flow between two components. When closed, electricity is prohibited from flowing, thus breaking the circuit. However, there are also mechanical switches that perform this same basic function. So, what’s the difference between membrane switches and mechanical switches? And which one is right for your business?

Material of Construction

Although there are exceptions, most mechanical switches are made of copper and plastic. Copper, of course, is one of the most conductive materials on the planet, surpassed only by silver. Because its more readily available, though, copper is also cheaper and easier to source, making it a popular choice for the construction of mechanical switches.

Membrane switches, on the other hand, typically consist of an electrical switch that’s printed on Polyethylene terephthalate (PET) or Indium tin oxide (ITO) with conductive ink. It’s essential that conductive ink is used in a membrane switch. Otherwise, it won’t be able to control the flow of electricity. If a non-conductive ink is used, electricity won’t be able to flow through it. This is why most membrane switches feature copper, silver or graphite ink, all of which are conductive.

Flexible

Another way in which membrane switches differ from mechanical switches is that only the former is flexible. In fact, ASTM International — the Pennsylvania-based organization that develops technical standards — defines membrane switches as being “a momentary switch device in which at least one contact is on, or made of, a flexible substrate.” The keyword of this definition is “flexible,” meaning membrane switches can bend and flex — to some degree, at least — without breaking. Mechanical switches don’t offer this same benefit, making them ineffective for certain applications.

Durability

In addition to being flexible, membrane switches are strong and durable. There are even some types of membrane switches that feature water-resistant properties. When printer silver is replaced with copper and polyimide, for example, it creates a Kapton circuit. Kapton circuits have a higher current capacity and increased resistance to moisture than traditional membrane and mechanical switches.

Both membrane and mechanical switches are designed to control the flow of electricity. The former, however, is made of different materials, contains a flexible design, and offers a higher level of strength and durability.