Mechanical vs Membrane Keyboards: What’s the Difference?

During your travels on the gaming keyboard area of the internet you’ve probably noticed the words ‘membrane’ and ‘mechanical’ being tossed about with reckless abandon. Typically, the word ‘mechanical’ is used positively, but the word ‘membrane’ is denigrated. So, mechanical vs membrane, what’s the difference? Is one better? Let’s take a look.

When people go on about mechanical vs membrane keyboards, they’re referring to the way that the keyboard works.

The fundamental principle is the same. When you press a key, the downwards motion completes an electric circuit, sending a signal from the keyboard to the computer, and the keystroke is registered. However, the way the circuit is completed differs depending on whether you have a membrane or a mechanical keyboard.

A membrane keyboard uses two sheets of rubbery material placed on top of each other. Together, this sheet has small cavities within it, similar to bubble wrap. These cavities have one side of the electrical circuit we mentioned on each half, and the semi-rigid nature keeps them separate, so the circuit is kept open by default.

When you press a key, both halves of this cavity are pushed together, and the circuit is completed. When the key is released, the springy rubber material opens up again, opening the circuit back up.

This design of keyboard is reliable, very cheap, and is usually quite resistant to water, dust, and any other granules that often find their way into keyboards. Unfortunately, it's generally accepted that membrane keyboards don’t feel very good. Many people decry them as feeling ‘mushy’ or ‘squishy’, which is one of the reasons that mechanical keyboards have become so popular, but how do they work?

The same concept of closing a circuit to send a signal still applies to mechanical keyboards, however, in order to improve the tactile sensation, the mechanism differs. Instead of squishing two sheets of rubber together, instead there is a more complex and, yes, mechanical design.

Note: we’re using Cherry MX-style switches for this example. There are more exotic switches out there, but most are derived from the Cherry MX design.

In a mechanical key switch, there are two copper contacts positioned next to each other. At rest, these aren’t touching, keeping the circuit open. When you press a key, the keypress pushes a piece of plastic known as the stem, down. The stem has legs that poke out slightly, and these come into contact with one of the copper contacts. As the stem continues downward, the legs move the copper contact outward until it touches the other contact. This completes the circuit and sends the signal. A spring returns the stem to its resting position when you let go of the key..

All these moving parts are the reason that mechanical keyboards are more expensive, and the reason that they are preferred. You see, changing any of these parts can alter how it feels to press the key down. If you change the spring, the key can become easier or harder to press. If you change the shape of those legs we mentioned, you can introduce tactile differences, for example, adding a small bump in the legs makes the key become a little harder to press, before giving way. This is what people are referring to when they say a switch is ‘tactile.’

So, those are the two main ways that keyboards work, but if there are two types, both must be viable, right? So here are the pros and cons for mechanical and membrane keyboards.

That was very wordy wasn't it? Well, if you're not interested in the actual principles and engineering, here's a simple break down of the benefits and drawbacks of mechanical and membrane switches.

Pros –

• Cheap
• Reliable
• Water resistant

Cons –

• Less enjoyable typing experience
• More difficult to replace
• Cannot be customized

Pros –

• Nicer typing experience
• Different switches provide different tactile sensations
• Customizable

Cons –

• Expensive
• Can be fragile
• Generally not suitable for thin laptop-style keyboards