Solid State Buttons Give the Right Touch to Smartphones

While smartphones have seen numerous advances, one area where progress has lagged is in the buttons that activate various phone functions. Smartphones have retained electromechanical buttons that are prone to wear and do not always provide the tactile feedback that users desire.

Boréas Technologies, a company founded by CEO Simon Chaput in 2017, may have a solution in its solid-state haptic buttons for smartphones. The company’s Boréas CapDrive® Haptic Buttons replaces the old mechanical button interface with high definition, localized haptic buttons that can mimic the exact feel of a mechanical button while also enabling more immersive, realistic and satisfying touch experiences.

Chaput, during a recent interview with Design News, noted that mechanical buttons have continued to predominate on smartphones since those products emerged in the 2000’s decade. The solid state buttons Chaput developed came out of research he originally performed at Harvard University in 2013, and through Boreas, is now coming onto the market.

Enriching the User Experience

The Boréas CapDrive buttons will be available in two configurations: standard buttons that provide richer, more realistic button-click sensations, and sliders, which sense movement through swiping. Smartphone designers can use the new buttons, which use piezoelectric technology, to replicate the feel of existing mechanical buttons for simple tasks such as power on/off, while offering new experiences that still feel familiar to smartphone users.

According to the company, users pressing the haptic buttons will get the same partial button-depress sensation as with a DSLR camera when focusing the lens and the same full button depress feeling when “snapping” the shot. In addition, going online by phone will be easier, because the user can browse with one hand by using a haptic slider-button that feels like a trackwheel mouse, which even mimics the familiar tick-tick sensation on the fingertip as the pages scroll by.

Unlike mechanical buttons, the Boréas CapDrive Haptic Buttons can be programmed to provide subtle and localized effects on the buttons themselves. Chaput envisions the buttons not only giving a more camera-like feel to smartphone camera functions, but also provide an intuitive, interactive sensation to slider switches for smartphone games.

Piezoelectric Technology

The CapDrive Haptic Buttons are a platform based on the Boréas CapDrive BOS0614, a multichannel, ultra-low-power piezo haptic driver with integrated force-sensing. According to the company, the technology is more than a factor of 10x more power-efficient than mechanical technologies (e.g., strain, voice coil) as well as competitive piezo drivers. Zero power sensing keeps power consumption under 10 microamps in sleep mode, allowing the chip to wake up in less than 100μs when it detects a click.

The buttons are also IP68-rated waterproof and are natively immune to environmental contaminants such as dust or oil. The buttons are packaged in a WLCSP measuring 2.1 x 2.5 x 0.5 mm. The BOS0614 driver’s small size and four channels support up to four buttons in a miniature footprint.

Aesthetically, the haptic buttons streamline industrial design by losing mechanical button “bumps.”

Boreas is now offering the buttons to OEMs, and is also making a reference design available to ease design-in.