BARCELONA — Now that motion (Nintendo Wii), touch (Apple iPhone) and voice (Amazon’s Alexa) are old hat, “touchless” looms large and lucrative as the next user interface (UI) of choice for consumer devices. Or so attendees at this year’s Mobile World Congress (MWC) are being told.
“Major consumer electronics breakthroughs have always been triggered by UI revolution,” Michelle Kiang, CEO of Chirp Microsystems, told us in an interview here on the first day of the conference.
Chirp's MEMS ultrasound sensor SiP (Source: Chirp Microsystems)
Chirp offers a single-chip ultrasonic time-of-flight (ToF) sensor, allowing users to interact with wearable devices without actually touching screens, or to interact with devices sans a screen.
Although Kiang isn’t saying “touchless” – based on ultrasonic sensing – will replace other existing UIs, she believes “it can add another modality” to wearables, AR/VR, smartphones and even automotive.
UC Berkeley & Davis heritage
Chirp Microsystems, a Berkeley, Calif.-based startup with 15 employees, came to the MWC this week to launch the company’s first high-accuracy, ultra-low power ultrasonic sensing development platform for wearables.
Smartwatches, typical of many wearables, have limited screen sizes that suffer from the “fat finger” effect, said Kiang. By embedding MEMS-based ultrasonic ToF sensors inside a smartwatch, the finger – fat or otherwise – uses gestures, without screen contact, to control watch functions.
Even a better example might be a wearable wristband. Today’s band – with no space to fit a screen in – is powerless to directly interface with its wearer. But with ultrasonic ToF sensors tiny enough to put inside a band or ring, “Suddenly, popular wearable bands become interactive,” said Kiang.
Chirp's ultrasonic sensors embedded inside a ring
Chirp’s ToF sensor is in a 3.5 mm land grid array (LGA) package - similar to a MEMS microphone. It operates on a single 1.8V supply, according to the company. With an I2C interface, it’s now easy to integrate the ToF sensor into consumer electronics products.
MEMS and mixed-signal CMOS ASIC
Chirp has developed both a MEMS ultrasound transducer and an accompanying mixed-signal CMOS ASIC, and combined them in a system-in-package.
The ToF sensor’s on-board microprocessor enables always-on operation for wake-up sensing applications. It has a pulse-echo sensing range greater than 1 meter and consumes only 9 µA at 1 Hz sample rate, according to the company.
The miniaturization of MEMS ultrasound sensors – a breakthrough made by a team of researchers and engineers at University of California Berkeley and Davis – became the foundation of the startup established in 2014.
Both the IP and key researchers have transferred from the universities to Chirp. The team includes David Horsley, a professor in the department of mechanical and aerospace engineering, University of California Davis, in addition to PhD students and postdocs at both Berkeley and Davis. Today, Horsley is Chirp’s CTO.
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