Membrane switches are on the rise. Like all switches, they are circuit-controlling devices that feature a conductive path. Electricity can flow through a switch when it’s closed. If a switch is open, electricity won’t be able to travel through it. Membrane switches feature a similar conductive path that can be opened or closed, but they use a different design than their traditional counterparts.
According to ATSM International, a membrane switch is a circuit-controlling device in which “at least one contact is on or made of a flexible substrate.” Membrane switches are comprised of layers that are laminated together. Once laminated, the layers will form a fully functional switch. Activating the switch will open or close its conductive path. When shopping for a membrane switch, though, you may notice that some of them feature a protective topcoat.
What Is a Protective Topcoat?
A protective topcoat is an outer layer that’s applied to the surface of a membrane switch. As the name suggests, it’s used to protect the membrane switch from damage.
Exploring the Construction of a Membrane Switch
While available in different types, all membrane switches have an overlay. It’s the outermost layer of a membrane switch that you press or touch to interact with the switch.
Some membrane switches feature a polyester overlay. Other membrane switches feature a polycarbonate overlay. There are even membrane switches with a blended overlay consisting of two or more materials.
Why Choose a Membrane Switch With a Protective Topcoat
Whether a membrane switch has a polyester, polycarbonate or blended overlay, it may feature a protective topcoat as well. Protective topcoats are transparent layers that are applied over the top surface of a device or object. In the case of membrane switches, the protective topcoat may sit on top of the overlay. Why should you choose a membrane switch with a protective topcoat exactly?
Membrane switches with a protective topcoat are less likely to succumb to scratches than those without a protective topcoat. Scratches can occur from normal use with switches. Over time, the overlay may become scratched. Scratches, though, are less likely to occur if you choose a membrane switch with a protective topcoat.
A protective topcoat will also protect the membrane switch from sun exposure. Prolonged exposure to sunlight can damage overlays. The colors of the overlay may begin to fade, and you may no longer be able to identify the button legends or graphics. A protective topcoat will serve as a barrier that blocks ultraviolet (UV) light from reaching the membrane switch’s overlay.