2019-323 A Battery-Less Wirelessly Powered Dielectric Sensor

Summary:

UCLA researchers in the Department of Electrical and Computer Engineering have developed a novel a 2.73 mm² fully integrated wirelessly powered frequency-shift based dielectric sensor with on-chip antennas.

Background:

The Internet of Things (IoT) offers connectivity across all devices, from cellphones to household appliances to large city infrastructures. To maintain and expand the connectivity of this ever growing network, reliable sensors are needed with sensing, computation and communication capabilities. Simultaneously, these sensors need to meet the ever growing need to be wireless, long-range charging, have a small footprint and low-cost.

Innovation:

UCLA researchers in the Department of Electrical and Computer Engineering have developed a battery-less, wirelessly-powered frequency shift based dielectric sensor. The sensor microchip is made in an 180 nm CMOS process and contains all the parts needed to be entirely self-contained. Specifically, the sensor includes an energy-harvesting frontend, a power management unit, a dielectric sensing oscillator, and on-chip receiving and transmitting antennas. The sensor is just 2.77 mm² in size, powered wirelessly via on-chip antenna at 9.8 GHz and has an operating distance of 6 cm, making it practical for use in all small and (when used in array) large IoT devices.

Patent:
Systems and Methods for Battery-Less Wirelessly Powered Dielectric Sensors

Potential Applications:

• 3D gesture sensing for mobile devices
• Oil and gas leakage sensing
• Hazardous gas sensing

Advantages:

• High power harvested at 9.8 GHz
• Small footprint of 2.73 mm²
• Long wireless charging distance of 6cm
• Oscillation frequency 3.66 GHz to 4 GHz

Related Materials:

• Sun, Yuxiang, and Aydin Babakhani. "Wirelessly-Powered Dielectric Sensor With On-Chip Antennas in 180 nm SOI CMOS Process." IEEE Sensors Journal 19.7 (2018): 2613-2620.

Development to Date:

A preliminary microchip pixel was fabricated in 180nm CMOS process. The miniaturized microchip was only 3.9 x 0.7 mm² in size and could be wirelessly powered, and send back signal at different frequency from 3 GHz to 4 GHz. The chip was used to successful sense different dielectric material, including oil and epoxy.