Brian P. Otis

A 3-

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.

\mu\hbox{W}

A low-power low-phase-noise 1.9-GHz RF oscillator is presented. The oscillator employs a single thin-film bulk acoustic wave resonator and was implemented in a standard 0.18-/spl mu/m CMOS process. This paper addresses design issues involved in codesigning micromachined resonators with CMOS circuitry to realize ultralow-power RF transceiver components. The oscillator achieves a phase-noise performance of -100 dBc/Hz at 10-kHz offset, -120 dBc/Hz at 100-kHz offset, and -140 dBc/Hz at 1-MHz offset. The startup time of the oscillator is less than 1 /spl mu/s. The oscillator core consumes 300 /spl mu/A from a 1-V supply.

CMOS Glucose Sensor for Wireless Contact-Lens Tear Glucose Monitoring

A 128-bit, 1.6 pJ/bit, 96% stable chip ID generation circuit utilizing process variations is designed in a 0.13 mum CMOS process. The circuit consumes 162 nW from a 1 V supply at low readout frequencies and 1.6 muW at 1 Mb/s. Cross-coupled logic gates were employed to simultaneously generate, amplify, and digitize the random circuit offset to create a stable unique digital chip ID code. A thorough statistical analysis is presented in order to explore the ID circuit reliability and stability. Two ID generators with different layout techniques were designed and fabricated to provide a performance comparison of power consumption, ID stability, and ID statistical robustness.

A 300-/spl mu/W 1.9-GHz CMOS oscillator utilizing micromachined resonators

A fully integrated 2GHz super-regenerative transceiver is implemented in a 0.13 /spl mu/m CMOS process. The transmit and receive paths utilize BAW resonators, yielding a 450 /spl mu/W 1V RF front-end and a transmitter delivering 380 /spl mu/W with 23% efficiency. At 5kb/s, the receiver achieves a sensitivity of -100.5dBm for 10/sup -3/ BER.

A Digital 1.6 pJ/bit Chip Identification Circuit Using Process Variations

A 128b 6.3pJ/b, 96%-stable chip-ID generation circuit using process variation is designed in a 0.13mum CMOS technology. The circuit consumes 162nW from a 1V supply at low readout frequencies and 6.34muW at 1 Mb/s. Two layout techniques are designed and fabricated to provide a performance comparison of power consumption and ID reliability

A 400 /spl mu/W-RX, 1.6mW-TX super-regenerative transceiver for wireless sensor networks

This paper presents an ultra-low power batteryless energy harvesting body sensor node (BSN) SoC fabricated in a commercial 130 nm CMOS technology capable of acquiring, processing, and transmitting electrocardiogram (ECG), electromyogram (EMG), and electroencephalogram (EEG) data. This SoC utilizes recent advances in energy harvesting, dynamic power management, low voltage boost circuits, bio-signal front-ends, subthreshold processing, and RF transmitter circuit topologies. The SoC is designed so the integration and interaction of circuit blocks accomplish an integrated, flexible, and reconfigurable wireless BSN SoC capable of autonomous power management and operation from harvested power, thus prolonging the node lifetime indefinitely. The chip performs ECG heart rate extraction and atrial fibrillation detection while only consuming 19 μW, running solely on harvested energy. This chip is the first wireless BSN powered solely from a thermoelectric harvester and/or RF power and has lower power, lower minimum supply voltage (30 mV), and more complete system integration than previously reported wireless BSN SoCs.

A 1.6pJ/bit 96% Stable Chip-ID Generating Circuit using Process Variations

We present the design, construction and in vivo rabbit testing of a wirelessly powered contact lens display. The display consists of an antenna, a 500 × 500 µm2 silicon power harvesting and radio integrated circuit, metal interconnects, insulation layers and a 750 × 750 µm2 transparent sapphire chip containing a custom-designed micro-light emitting diode with peak emission at 475 nm, all integrated onto a contact lens. The display can be powered wirelessly from ~1 m in free space and ~2 cm in vivo on a rabbit. The display was tested on live, anesthetized rabbits with no observed adverse effect. In order to extend display capabilities, design and fabrication of micro-Fresnel lenses on a contact lens are presented to move toward a multipixel display that can be worn in the form of a contact lens. Contact lenses with integrated micro-Fresnel lenses were also tested on live rabbits and showed no adverse effect.

A Batteryless 19

For fully autonomous implantable or body-worn devices running on harvested energy, the peak and average power dissipation of the radio transmitter must be minimized. Additionally, link symmetry must be maintained for peer-to-peer network applications. We propose a highly integrated 90 μW 400 MHz MICS band transmitter with an output power of 20 μW, leading to a 22% global efficiency - the highest reported to date for low-power MICS band systems. We introduce a new transmitter architecture based on cascaded multi-phase injection locking and frequency multiplication to enable low power operation and high global efficiency. Our architecture eliminates slow phase/delay-locked loops for frequency synthesis and uses injection locking to achieve a settling time <;250 ns permitting very aggressive duty cycling of the transmitter to conserve energy. At a data-rate of 200 kbps, the transmitter achieves an energy efficiency of 450 pJ/bit. Our 400 MHz local oscillator topology demonstrates a figure-of-merit of 204 dB while locked to a stable crystal reference. The transmitter occupies 0.04 mm2 of active die area in 130 nm CMOS and is fully integrated except for the crystal and the matching network.

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Rapid development in miniature implantable electronics are expediting advances in neuroscience by allowing observation and control of neural activities. The first stage of an implantable biosignal recording system, a low-noise biopotential amplifier (BPA), is critical to the overall power and noise performance of the system. In order to integrate a large number of front-end amplifiers in multichannel implantable systems, the power consumption of each amplifier must be minimized. This paper introduces a closed-loop complementary-input amplifier, which has a bandwidth of 0.05 Hz to 10.5 kHz, an input-referred noise of 2.2 μ Vrms, and a power dissipation of 12 μW. As a point of comparison, a standard telescopic-cascode closed-loop amplifier with a 0.4 Hz to 8.5 kHz bandwidth, input-referred noise of 3.2 μ Vrms, and power dissipation of 12.5 μW is presented. Also for comparison, we show results from an open-loop complementary-input amplifier that exhibits an input-referred noise of 3.6 μ Vrms while consuming 800 nW of power. The two closed-loop amplifiers are fabricated in a 0.13 μ m CMOS process. The open-loop amplifier is fabricated in a 0.5 μm SOI-BiCMOS process. All three amplifiers operate with a 1 V supply.

W MICS/ISM-Band Energy Harvesting Body Sensor Node SoC for ExG Applications

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 mm2. 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.