"The tool itself is simple. A greyscale image of the UI graphics provides the haptics intent to our rendering engine, indicating what effect must be attributed to what pixel" explained LoPresti. Any image can be turned into a texture across 255 levels of friction, with pure white representing the highest friction and pure black the lowest friction”.
"We can change the haptic effects as fast as you refresh the image on display. You could feel the texture of sand, then rub it off the screen and feel a different texture underneath. We can layer the haptics too. For example a round button with clicks could have a different granularity level if you tap it once, or become a binary button (left or right click) upon a double tap" said the CEO.
For now, the company's demonstrators use off-the-shelf components, but in the future, Tanvas also wants to create a custom touch-display microcontroller integrating both the touch sensing and haptics functions, without having to synchronize two different components. And this would prove cost-competitive with any alternative touch and haptics solutions. The haptics are felt within a millisecond of touch detection.
The CEO also emphasized that this technology is completely solid-state, not only implemented without any moving parts, but also without having to vibrate the screen even through the use of piezoelectric actuators (also considered as solid-state technology compared to eccentric rotating mass motors).
This is an important distinction, LoPresti argued, because driving piezoelectric actuators at high frequencies to get the desired physical haptic effects through vibrations do come with some issues, namely buzzing noises and resonances which need to be dampened.
"In a car, if you want to use a vibrotactile solution, you have to engineer dampening hardware to attenuate unwanted vibrations, this adds cost and weight, so most OEMs try to avoid having to dampen their screen" he said.
"In our touch plus haptics solution, the touch panel is the coverlens, which makes the bill of materials compelling depending on the size and shape of the screen."