Membrane switches have become a popular alternative to traditional mechanical switches. Unlike their mechanical counterpart, membrane switches are printed on PET or ITO, typically featuring a conductive ink like copper, silver or graphite. There are several benefits associated with membrane switches, some of which include a low profile, compact design, integration with other control systems, and ease of cleaning. Furthermore, membrane switches support a variety of different backlights, including light-emitting diode (LED), optical fiber and electroluminescent (EL).
While membrane switches today are commonly found in household appliances, air conditioners, remote controls and other electronic devices, they are still relatively new when compared to mechanical switches. So, how exactly were membrane switches invented?
Membrane switches have origins dating back nearly three decades. At the time, however, they were somewhat unreliable and often resulted in erroneous circuit activation. This, of course, restricted their utility in real-world applications, with most companies and consumers preferring the more reliable mechanical switch instead.
Some of the world’s first membrane switches were designed of polycarbonate materials. This was a cheap and readily available material, but it wasn’t particularly effective for this application. Polycarbonate membrane switches were susceptible to breakage, which typically occurred between the keys. Over time, constant usage would degrade and wear down the keys to the point where small fractures in the polycarbonate material would occur. Furthermore, these early model membrane switches didn’t have any tactile feedback, which is another reason why so many people preferred mechanical switches at the time.
Nonetheless, this wasn’t the end of the road for membrane switches; manufacturers continued to enhance and improve the technology to make it better. One such change that marked a substantial improvement in the membrane switch’s design was the use of polyester instead of polycarbonate. Polyester proved to be stronger, more rugged, and able to withstand constant use without breaking or otherwise cracking like its polycarbonate counterpart.
Of course, this also led to the advent of tactile feedback, which has become a popular feature found in membrane switches. Additionally, manufacturers began to use backlights in their membrane switches. LED, EL and fiber optics are the three most popular backlight options used in membrane switches.
Today, membrane switches are one of the world’s most popular types of electrical switches. They are typically designed with four layers, with the top layer featuring the graphic interface between the actual machine and the user. Hopefully, this gives you a better understanding of the history and origins of the membrane switch.