Regardless of whether you’re in the industrial or consumer electronics business, your products’ HMIs will influence whether or not the user has an enjoyable experience. Furthermore, a product with a great HMI is more likely to succeed than one with a frustrating one. People are also becoming ever-more discerning when it comes to HMIs: witness the number of consumers you see in electronics shops, getting their hands on products to try them out before they buy.
Of course, as new HMI technology comes to prominence, other things fall by the wayside. Mechanical switches and keys – long-time electronics mainstays – are disappearing. Resistive touchscreens have largely been replaced by capacitive ones, which most of us first encountered in our smartphones and tablets. These ubiquitous devices have shown us the good, the bad and the ugly of capacitive technology. Too sensitive and you get false triggering. Not sufficiently sensitive and they become difficult to use. Moisture and electrical noise can interfere, and many capacitive touch panels don’t respond well when you have gloves on.
HMI designers face another constant challenge: increasing device complexity. This is largely borne out of manufacturers’ incessant drives to gain competitive edge by cramming ever-more functions into their products. Every new function they include needs to be controlled in some way: typically, this has meant adding physical buttons or menu items.
Force-sensing technology: the key to simpler user interfaces
One way to accommodate the drive for more functionality without making HMI’s even more complex, is to take advantage of tactile-based controls. As an HMI designer, if you have a way of capturing force in an analogue way – with the required levels of precision, consistency and reliability – you add a whole new dimension to how people can control your product.
Where a button was once just a switch, you can now make it an on/off switch and intensity controller, able to increase the speed of a drive motor or the brightness of a light based on how hard you press or squeeze. Even a toddler knows squeeze harder, go faster.
Expand this force sensitivity to whole surfaces, and you can enable people to access new functions with appropriate intuitive presses and squeezes – rather than confronting them with the complexity of lots of buttons.
Introducing Quantum Tunnelling Composites
Sensor solutions using Quantum Tunnelling Composites or QTC are easy-to-implement, cost-effective, and enable designers to add the features they want while keeping user interfaces clean and simple.
Force touch sensors that use QTC overcome the shortcomings of other sensor technologies in a unique way. QTC is an economical and flexible polymer which, when no force is applied, is an insulator. As you increase the pressure on it, its conductivity progressively grows.
Use cases for QTC
Combined with the right electronics, QTC is ideal for use as a straightforward, sensitive, long-lasting switch. It can also be used to enable progressive control of system parameters, such as motor speed, brightness, or volume without the cost and complexity of an additional control input.
QTC-based force sensors are a great option for designers creating multi-touch displays and panels, and you can tune each touchpoint to create the user experience you want. Other benefits include noise immunity and good temperature stability, while development time can be kept short, thanks to its relatively simple firmware and software requirements. This combination of design simplicity, robustness, and intuitive use can add a new dimension to future HMIs.
Author profile:
Mike Levin is chief commercial officer at Peratech
