Modern-day gadgets and electronics always include some type of control or keypad for managing functions. While there are several kinds of keyboards, the two most commonly used are mechanical keypads and membrane keypads. Membrane keyboards are often seen in many medical devices. But apart from their application in the medical field, here is a closer look at the features of a membrane keypad and why it may be right for your intended use.
What is a membrane keypad?
Membrane keypads consist of keys or pads with printed symbols. A membrane keypad does not contain individual keys; instead, the whole pressure pad does not contain any breaks but is a single surface stretched over the device. A single surface gives a membrane keypad the added advantage of being more compact than a mechanical keyboard. A membrane keypad comprises three essential parts:
- The bottom layer which connects to the rest of the device
- The middle layer which is inert
- Top layer with symbols
The bottom layer consists of several conductive traces which will trigger the appropriate command when a symbol is pressed. There are also two design variations for membrane keypads. There is a flat membrane key where all symbols are printed on the same pad, while the other is a dome design which gives the symbols better tactile feedback by shaping them into domes.
What are the advantages of using a membrane keypad?
There are many advantages to using a membrane keypad over its mechanical counterpart. First, a membrane keypad is smaller than a mechanical keyboard which makes them suitable for smaller devices or for slimmer gadget designs which won’t be feasible for a mechanical keypad. Another advantage of using a membrane keypad is that it does not produce any noise.
One of the reasons why membrane keys are preferred for medical devices is that there are no grooves and spaces where bacteria and dirt can accumulate. Membrane keys are more hygienic to use. Membrane keys also last longer than mechanical keypads.
Drawbacks to using a membrane keypad
Although the benefits of using a membrane keypad are numerous, it is not without disadvantages. Perhaps the most commonly highlighted challenge in using a membrane keypad is that it lacks tactile feedback. Lack of tactile feedback poses a difficulty for some in making sure that the right button is pressed. To overcome this, design engineers use dome-type membrane keys which help mimic the effect of a mechanical keypad in producing tactile feedback.
Common uses of membrane keypads
There are a variety of suitable applications for membrane keypads — the most common being in the medical field. A wide range of medical devices such as X-ray machines, dental equipment, and portable diagnostic devices often have membrane keypads used for controlling their function. Apart from this, membrane keys are also widely applied in aerospace equipment and industrial process control machines.
Because membrane keys are robust and durable, they can withstand the effects of rugged wear and tear. Membrane keys are generally more reliable and highly conductive in comparison with mechanical keyboards.