With sleek design and high-tech features driving the automotive industry, automakers are increasingly exploring the use of touchscreens in consoles and dashboards. Touchscreen technology lets drivers and passengers control a number of functions, from selecting music and adjusting speaker volume to operating navigational software. But while automakers would surely like to expand the use of capacitive touch technology, in particular, there are hurdles that must first be cleared. Luckily, tactile pressure sensing technology just might hold the key to enabling that significant leap forward.
Chief among the obstacles to further integration of capacitive touch technology in automobiles is preventing accidental user input. Think of how difficult it can be to press the correct button or key on a smartphone in even the most stable of environments; now imagine trying to do so in driving conditions that cause the fingers to bounce up and down. The consequences of accidental input when it comes to automobile operation range from annoying (selecting the wrong radio station) to potentially dangerous (unintentionally deactivating cruise control).
Ensuring that every command is entered intentionally and correctly is, thus, a crucial factor -- which is why many touchscreens in cars right now are actually based on resistive technology. Resistive touchscreens require that two films are pushed together, meaning a user must apply a certain amount of deliberate force to input commands. This is also why many of the critical functions, such as those that can be controlled from the steering wheel, are, to this day, operated via mechanical buttons.
Tackling this challenge head on, Pressure Profile Systems (PPS) is developing a tactile switch, a more reliable solution that could help make capacitive touch technology a more viable option in cars. The tactile switch enhances capacitive touch technology by adding the dimension of force via the inclusion of a second electrode. This means that it would be possible to require that a certain level of force be applied before the switch is activated, thus solving the problem of unintentional input without increasing the cost or sacrificing the benefits of capacitive touch technology.
In addition to safely and reliably, controlling a broader set of functionality than is currently advisable with capacitive touch technology, the tactile switch could leverage the force functionality to improve the user interface and make certain operations more precise. Consider how difficult it can be to slightly open a conventional power window; getting the timing right can be tricky. A window controlled by a pressure-sensitive tactile switch, however, could conceivably be responsive to touch. For example, a light touch might open the window slowly to control the position precisely, while a heavier touch could open the window faster.
From a design perspective, tactile switch technology offers a smooth and seamless input area that opens up a new range of possibilities. Imagine a dashboard that consists of a single sheet of plastic with printed markings -- rather than physical buttons -- indicating where certain functions can be activated. The look would certainly be smoother and cleaner than what’s currently provided. Furthermore, because they include a second ground layer, tactile switches can be embedded into various surfaces.
Conventional capacitive sensors measure electrical properties, making them susceptible to interference from metal or environmental factors like rainwater, as anyone who has tried to open or unlock a car door using the embedded capacitive touch sensors can attest. Tactile switches, by contrast, measure mechanical, not electrical, properties. This means they’re immune to the effects of rain, and can even be embedded behind chrome, which is an especially exciting prospect.
As the world’s automakers continue to improve the user experience, dashboard controls and other functions will have to become simultaneously sleeker and simpler in appearance and more sophisticated in operation. And tactile pressure sensing technology could be the game changer.