Smartphone with Boréas solid-state side buttons

Mobile Phone
SSB - Slider

Redefining Touch in Mobile Devices

Touch Reimagined

Block diagram of a smartphone solid-state button: application processor, MCU, BOS1921 piezo driver and piezo actuator over I2C

The Solid-state Slider Demo

Finger pressing a solid-state side button on a smartphone

Breaking the Touch Interaction Plateau

Icon for localized HD haptic feedback

Localized HD Haptic Feedback

Boréas SSB plays HD haptic feedback right where the finger touches, instead of shaking the whole phone. Each click, slide and press can have its own waveform.

Icon for seamless integration

Seamless Integration

The haptic module matches the footprint of current mechanical switches, so it drops in without changing the assembly process.

Icon for power efficiency

Power Efficiency Redefined

It consumes up to 10 times less power than competing piezo drivers, extending battery life without sacrificing haptic quality.

Feel the click before you commit.

Don't Just Spec It. Feel It.

Request the Solid-State Button Devkit

Smartphone Solid-State Buttons: FAQ

What is a solid-state button on a smartphone?

A side button with no moving parts, whose function is defined in software. A sensor detects the press, and a piezo actuator plays a waveform under the finger that feels like a mechanical click. The button can change role with the app in use: a shutter in the camera, a scroll wheel in the browser, a trigger in a game.

What can a solid-state side button do that a mechanical button can't?

A mechanical button can only click. A solid-state button can be tuned to whatever the UX calls for: a slider, a two-step button, a zoom control, a clicking scroll wheel or a press with its own haptic signature. A light press can focus the camera and a full press take the photo, like a DSLR shutter.

Will solid-state buttons drain a smartphone battery?

Not meaningfully. CapDrive drivers recover the energy stored in the piezo actuator after each click and use up to 10 times less power than competing piezo drivers. The BOS1921 draws 0.5 µA in sleep mode and consumes power only while a haptic effect plays.

Why use a piezo actuator instead of the phone's LRA for button feedback?

Because the two actuators do different jobs. An LRA is good at general notifications: it shakes the whole phone so you feel an alert in your hand or pocket. A button needs a localized click, tuned to your liking and felt right under the finger. A piezo actuator delivers that by moving only the button surface and starting and stopping almost instantly. An LRA can't.

How can I prototype a solid-state smartphone button?

The Piezo Solid-State Button Devkit with CapTouch (BOS1921-KIT-C03) lets your team feel the piezo click and tune presses, slides and force thresholds before committing to a design. For the basics of the technology, see our solid-state button overview.

Download the Application Brief

Complete the form below to receive our detailed application brief. This comprehensive document provides an in-depth description of the solid-state button technology and guides you in selecting the right components for your specific application needs.