Membrane Switch - Flexible Pet And Ito Layers, Touch Activated Interface For Industrial Controls And Home Appliances

A membrane switch is an electrical switch for turning on and off a circuit. It differs from a mechanical switch, which is usually made of copper and plastic parts: a membrane switch is a circuit printed on a PET or ITO. The ink used for silk screening printing is usually copper / silver / graphite filled and therefore conductive.
The ASTM defines a membrane switch as a momentary switch device in which at least one contact is on, or made of, a flexible substrate.
A membrane switch is a multi layered switch device that is touch activated to make or break the electrical connection of a particular switch element. Membrane switches have become popular for use in industrial controls, home appliances, office equipment and automotive applications. Most often, membrane switches are designed for intended use as keyboard, key pad, or front panel interfaces to provide instructions from a user to operate various items, such as computers, manufacturing equipment and vending machines. Membrane switches normally employ a pair of stacked flexible membranes having opposed contacts printed on their facing surfaces. An intermediate layer is disposed between the outer two layers and acts to isolate the switch circuit patterns from each other. Electrical conductors, also printed on the facing surfaces of the membranes, communicate electrical signals to and from the contacts.