How Do Membrane Switches Work?

Looking into how membrane switches work?

A membrane switch is a human-machine interface (HMI) that is constructed using printed conductive inks, plastic films (membranes), and flexible materials.

As complicated as this may sound, there is a simple way to think about membranes switches. Basically, they provide a connection between you and your favorite devices. For example, if you use a keyboard for your desktop computer or a remote to control your television, you’re using a membrane switch.

Often in a membrane switch, conductive inks are printed onto the plastic films. They work to temporarily open and close an electrical circuit so that the device or appliance can be used properly.

Membrane switches are compact and this makes them perfect for use in small household appliances, health gadgets, and industrial equipment.

Types of Membrane Switches

There are two types of membrane switches – tactile and non-tactile. The former uses a small dome to create a button (such as on a remote). The latter uses a switch without a button (such as with LED indicators).

Generally, consumers tend to prefer tactile membrane switches. There’s something satisfying about the action of pressing a button to perform an action. However, non-tactile membrane switches are usually more efficient, longer-lasting, and more affordable.

How a Membrane Switch Works

The initial versions of membranes switches were invented back in the 1970s. Since then, they have developed into more complex, sophisticated systems.

Membrane switches work using open circuits with conductive inks. There are two main layers. The top layer is an overlay with buttons or keys that can be seen and pressed by the user.

The bottom layer consists of two circuits that contain films or membranes that are printed in conductive ink (usually silver or copper). The open circuit corresponds to specific buttons that the user can press to perform a specific action.

The circuit lies open until a button is pressed or pressure is applied to a specific area of the device or appliance. After this point, an area of the circuit is activated and causes the appropriate response. 

Using the example of a television remote, a user will press the volume button to make the sound louder. When the ‘+’ volume button is pressed by the user, it activates a specific part of the circuit.

When this area is activated, a processing unit receives the signal and causes the necessary output signal to be produced. This output signal is an increase in the television’s volume.

Main Applications of Membrane Switches

The applications for both tactile and non-tactile membrane switches are vast. They can be found in homes, warehouses, manufacturing areas, construction sites, and healthcare facilities.

Here are some specific applications for a membrane switch:

Household devices and appliances – remotes, computer or laptop keyboards, HVAC systems, microwaves, and washing machines

• Gyms – cardio machines or electronic body analysis equipment or weighing scales
• Healthcare facilities – emergency buttons, IV pumps or syringe drivers, feeding pumps, patient monitoring systems, motorized hospital beds, and various types of scanning equipment
• Industrial or manufacturing areas – motorized machinery and devices
• Laboratories – automation equipment, analysis equipment, and electronic devices

Membrane Switches are All Over

Now that you know how membrane switches work, as well as practical applications, you will notice them all around you. Look out for this amazing tech in your everyday life.