When researching keyboard technologies, you’ll probably come across membrane. Membrane keyboards are commonly used with computers. Some of them are built directly into laptops, whereas others are sold and used separately as an external device. Regardless, membrane keyboards are a popular alternative to mechanical keyboards. What is a membrane keyboard exactly?

Overview of Membrane Keyboards

Also known as a membrane-switch keyboard, a membrane keyboard is a type of keyboard that’s characterized by the use of a thin and flexible layer. This membrane layer serves as the keyboard’s switches. All keyboards have switches. A switch is simply a mechanism that controls a circuit. There’s typically a single switch for each key. In a membrane keyboard, though, the switches are embedded in a flexible membrane layer.

How Membrane Keyboards Work

Membrane keyboards work using a membrane layer, which is responsible for each of its switches. The membrane layer is typically made of polyester. As you may know, polyester is an elastic material that’s more forgiving than stiff or rigid materials.

When constructing a membrane keyboard, manufacturers use a sheet of polyester that’s printed with conductive traces. The sheet of polyester is cut into the appropriate size, after which it’s folded three times. After cutting and folding the polyester sheet, manufacturers bond it with the keyboard’s other layers via ultrasonic welding.

Advantages of Membrane Keyboards

Aside from being popular, membrane keyboards offer several advantages over other types of keyboards. They are available in smaller sizes and with a lower profile, for example. With a polyester layer, membrane keyboards aren’t large or bulky. They support a variety of sizes, with many membrane keyboards being small and having a low profile.

Membrane keyboards are also resistant to liquids. They are sealed so that water, beverages or liquids can’t reach the circuits below the keys. If you’re looking for a keyboard to use in a humid environment — or other environments where humidity is a concern — you may want to choose a membrane keyboard for this reason.

Because they are resistant to liquids, membrane keyboards are long-lasting. They’ll usually last longer than other types of keyboards. As a result, a membrane keyboard is a smart investment.

You can also choose backlighting for a membrane keyboard. While optional, many membrane keyboards are designed with backlighting. Backlighting consists of embedded bulbs that illuminate the keyboard’s keys from behind. Some of the different backlighting options for membrane keyboards include electroluminescent (EL) and light-emitting diode (LED).