This paper presents a noninvasive wireless sensor platform for continuous health monitoring. The sensor system integrates a loop antenna, wireless sensor interface chip, and glucose sensor on a polymer substrate. The IC consists of power management, readout circuitry, wireless communication interface, LED driver, and energy storage capacitors in a 0.36-mm² CMOS chip with no external components. The sensitivity of our glucose sensor is 0.18 μA·mm^-2·mM^-1. The system is wirelessly powered and achieves a measured glucose range of 0.05-1 mM with a sensitivity of 400 Hz/mM while consuming 3 μW from a regulated 1.2-V supply.

By utilizing a differential tunable active inductor for the LC-tank, a wide tuning-range CMOS voltage-controlled oscillator (VCO) is presented. In the proposed circuit topology, the coarse frequency tuning is achieved by the tunable active inductor, while the fine tuning is controlled by the varactor. Using a 0.18-mum CMOS process, a prototype VCO is implemented for demonstration. The fabricated circuit provides an output frequency from 500 MHz to 3.0 GHz, resulting in a tuning range of 143% at radio frequencies. The measured phase noise is from -101 to -118 dBc/Hz at a 1-MHz offset within the entire frequency range. Due to the absence of the spiral inductors, the fully integrated VCO occupies an active area of 150times300 mum²

We present progress toward a wirelessly-powered active contact lens comprised of a transparent polymer substrate, loop antenna, power harvesting IC, and micro-LED. The fully integrated radio power harvesting and power management system was fabricated in a 0.13 μm CMOS process with a total die area of 0.2 mm ² . It utilizes a small on-chip capacitor for energy storage to light up a micro-LED pixel. We have demonstrated wireless power transfer at 10 cm distance using the custom IC and on-lens antenna.

This article presents a nanowatt CMOS voltage reference using self-biased and capacitively coupled schemes for improving the power supply rejection ratio (PSRR) and settling time without power-intensive auxiliary amplifiers and bias circuits. The chip was fabricated in a 0.18-μm CMOS process. With the proposed schemes, the design can achieve a 1% settling time of 0.2 ms and a -73.5-dB PSRR at 100 Hz while only consuming 1.8 nW. The average temperature coefficient of 15 chips is 62 ppm/°C in a temperature range from -40 °C to 130 °C. The average voltage at 20 °C is 0.26 V, while the standard deviation is 1.1 mV and 3 σ accuracy is 0.43%.