Membrane switches are a tried and true solution but with technologies evolving, so are the ways people touch things. Sure, when you see a button, your first instinct is to push it, this is the reason why membrane switches are great options but have you ever walked up to a screen and touched it, expecting it to do something? Touch sensors are the now and the future of HMIs; they are everywhere.

How many times a day do you think you use a touch sensor? Probably more than you realize, laptop track pad, kitchen appliances, cell phones, kiosks, gas pumps, and the list goes on. These applications have taught us to want and expect touch screens to be on just about anything. With software, even the smallest of screens can have a powerful touch impact with just one simple gesture, a swipe. Functionality does not have to be compromised for size; take the Apple Watch for instance, it is 1/6 the size of a standard iPhone and has just about all the same capabilities as the phone.

There are pros and cons to everything, and as you know, it is important to weigh those out before considering a redesign. Don’t get me wrong, I’m all for the “if it’s not broke, don’t fix it” mantra, and for some products a touch sensor just won’t cut it, but it is important to consider, “how does our end user want to interact with this product?”

Why make the switch?

Touch sensors are becoming the technology of choice for modern applications and product specifications are becoming more sophisticated. What is the main reason people make the switch from membrane switch to a touch sensor? User experience! How people touch your product is the most important element of your success. When a human to machine interface has a poor user experience, that reflects on the product as a whole – you could have the most amazing (fill in the blank) machine but if the HMI isn’t up to par, neither is your product.

Making the switch has many appealing factors:

• Aesthetic value – give your product a sleek, professional look while staying technologically current
• Design flexibility – no compromises, designed to fit every need, want, and specification
  • Lens material and thickness – the sensor can be activated even through thick materials so it can be rugged for any application – don’t think of touch sensors like a fragile cell phone
  • Screen size – membrane switch buttons take up space, utilize that space for a larger screen, or reduce the screen size and eliminate buttons to keep things condensed
  • Backlighting can be added behind the sensor to accommodate high and/or low light situations
• Variable functioning – completely programmable to fit the end use
  • Sensitivity – easy to activate or programmed to require more deliberate touches and higher resistance to prevent false activation with accidental bumps and touches
  • Glove use – if the end user wears gloves, it can be programmed to work with them on so there is no need for the user to remove their gloves
  • Water – ever notice that cell phone screens go wonky when water gets on it? Because water conducts electricity, the phone registers that similarly to your finger touching the screen – not all touch sensors have to go wonky when water is on the screen, that can be programmed to be a non-issue for applications where water is present
• Waterproofing – since no holes need to be designed into the switch, waterproofing is easier than on membrane switches
• Low power consumption
• Faster activation response rate
• No mechanical failures due to deterioration of push buttons over time – less moving parts mean less wear and tear
• Flat front surface makes it easy to clean, read, and maintain

A good user interface can update the entire product, helping you to gain more market share, at a premium price point, and create some consistency and familiarity for the end user. There are many advantages to switching to a touch sensor, but it goes without saying, it is a big undertaking.

It is important to know that making the switch isn’t as easy as creating a new touch interface and swapping it out for the old membrane switch. The circuitry used to read a membrane is very different than the circuitry required to read a touch sensor, for this reason, companies typically wait for a new version/model, or a printed circuit board redesign.

Why not make the switch?

As stated earlier, membrane switches are a tried and true solution, reliable and can be designed to be user friendly (*power button here* *up arrow, down arrow* *flashing button to prompt next step*). For critical applications; when a lot is riding on the line, you want an interface that is consistent, every time. Let’s not forget about tactile feel; sure, a tactile sensation can be programmed into the sensor so you feel a little vibration when the button is activated, that is called a haptic response. But the feel of that little metal dome snapping under your finger after pushing a button, you can’t beat it. Sticking with a membrane switch would ensure you don’t lose that reliable crisp snap of a button.

It is also easy to stay with what works and wait for a competitor to invest the time and money into making the switch, then you will know if it would be worth the effort on your end. If a competitor’s product with a new interface fails in the market and they end up switching back to their original switch, you can rest easy.

It’s nice to have options.

Now that you know the pros and cons of making the switch, reconsider the question: “how does our end user want to interact with this interface?”

How people touch your product is critical to your success. Find a supplier with reliable solutions, experienced engineers to help design the interface without compromise in the most cost effective way, and intuitive and responsive designs.