SILICON
This is the part that earns the right to claim anything above it. Each card says what the chip sensed, what I owned on it, and where you can check.
Piezoelectric micromachined ultrasonic transducers built monolithically on CMOS: the sensor, its analog front end, and an MCU on one die. The imaging chain reads a fingerprint through glass and metal by transmit beamforming and pulse-echo timing.
Chip lead, multiple generations · mixed-signal front end, high-voltage pulser, system bring-up
An ultrasound touch and force controller that turns an ordinary surface into a button. Sensor, analog front end, MCU, and the sensor-fusion algorithm all live on one chip, so a button can be placed behind metal with no hole and no moving part.
Chip lead · architecture, mixed-signal front end, high-voltage pulser, on-chip sensing algorithm
A multi-modal human-machine-interface SoC: capacitive touch, ultrasound touch and slider, and piezoelectric force sensing, fused on-chip. One part replaces the controller, the discrete force front ends, and the glue between them.
Chip lead · architecture, mixed-signal front end, high-voltage drive, sensor fusion
A controller that keeps a camera lens clear by driving it ultrasonically. One chip carries the power conversion from the vehicle battery, the piezo driver, an on-chip Hall-effect current sensor that tracks the transducer's resonance, and the digital control.
Chip lead · architecture, piezo driver, on-chip current sensing
A time-of-flight rangefinder on a chip, small enough and low-power enough to sit in a consumer device. Precision frequency demodulation and low-jitter time measurement are what make a centimetre-scale echo readable at microwatt power.
Analog designer, prototype and first production generation · high-voltage pulser, PLL and frequency demodulation, mixer and filter design
The thesis chip. A PMUT array bonded to CMOS that images a fingerprint in three dimensions, including the ridge structure below the skin surface. It became the prototype for a commercial fingerprint sensor product line.
Chip lead and inventor · array and circuit co-design, high-voltage pulser, beamforming
A handheld, battery-powered ultrasound imager demonstrated at ISSCC. The interesting part is the drive side: getting enough voltage into a discrete piezo element from a battery, efficiently enough that the whole instrument runs at milliwatts.
Chip lead · high-voltage drive, integrated charge pump
A millimetre-scale implant that records neural activity and is powered and read out by ultrasound through tissue, with no battery and no wire. I built the ASIC the prototype used; the work went on to seed iota Biosciences.
ASIC provider · ASIC design, ultrasound wireless power transfer
A DC-DC converter that starts up from 50 mV with no battery and no external kick, turning the few tens of millivolts a thermoelectric generator produces into a usable supply rail. My first silicon, and still my second most-cited paper.
Chip lead · converter architecture, startup circuit
A large-area ultrasonic fingerprint sensor built on a thin-film transistor backplane with a piezoelectric polymer film, driven by a companion ASIC.
Analog designer · high-voltage drive, transmit beamforming
