Ultrasound sensor opens new touch sensing apps

The use of touch sensing as an interface is catching on thanks to technology advancements. A startup company, UltraSense Systems, has developed an ultrasound-based sensing technology for touch user interfaces. The technology can now enable a touch interface to be created through virtually any material of any thickness, including metal, glass, wood, ceramic and plastic. The technology can cost-effectively turn any surface into a virtual button or gesture.

UltraSense is leveraging the technology in its family of Touchpoint ultrasound sensors, which are already sampling and expected to be incorporated into several consumer and industrial devices in 2020.

“We have seen a shift in the way we interact with our devices, where digital has replaced mechanical, and the move to virtual buttons and surface gestures is accelerating,” said Mo Mahonia, founder and CEO, UltraSense Systems, in a statement. “The use of ultrasound in touch user interfaces has not been implemented in such a novel way until now. Our family of TouchPoint ultrasound sensor solutions enable new use cases that allow OEMs to bring a differentiated user experience with a wider variety of touch and gesture functions under virtually any material and material thickness.”  

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According to the company, competing technologies, including strain gauge, force touch and surface acoustic wave solutions that have extensive industrial and mechanical design restrictions like material thickness, integration complexity, and production calibration time. The use of ultrasound helps minimize integration difficulties and make for faster production calibration.

UltraSense said the technology could enable OEMs to remove mechanical buttons from smartphones to allow new industrial designs for next-generation 5G phones. In addition, the technology could enable touch interfaces or sliders on wearable devices, as well as on home appliances that use thick materials fabricated from stainless steel, glass, plastics, and ceramics. Another possibility is virtual buttons located in the steering wheel center and door panels using solid-state surfaces that are easy to clean in ride-sharing and shared vehicles.

UltraSense’s product line addresses smartphone, consumer/IoT, automotive and industrial user interface requirements. The TouchPoint family of sensors are contained in tiny packages and consume just milliamps of current in always-on mode. They are designed to operate independent of a product’s host processor with all the algorithm processing embedded in the sensor. The sensors can be used as a standalone power button, volume control, or shortcut keys for wake-on-touch sensing, by powering on the entire product with a simple touch. They can also form multi-functional user interfaces using a series of taps, holds and swipes. Sensors can be directly interfaced with power management and haptic driver ICs.

For applications where low power consumption is not a requirement, some Touchpoint sensors include large drivers with higher operating voltages to transmit the ultrasound beam through very thick solid metal. The transducer can also be shut off and the sensor used to drive piezo materials to cost-effectively support large touch sensing areas, like a mousepad in a laptop or trackpad in an automobile center console.