A Self-Powered Supply-Sensing Biosensor Platform Using Bio Fuel Cell and Low-Voltage, Low-Cost CMOS Supply-Controlled Ring Oscillator With Inductive-Coupling Transmitter for Healthcare IoT.

This paper proposes a self-powered disposable supply-sensing biosensor platform for big-data-based healthcare applications. The proposed supply-sensing biosensor platform is based on bio fuel cells and a 0.23-V 0.25- $\mu \text{m}$ zero- $V_{\text {th}}$ all-digital CMOS supply-controlled ring oscillator with a current-driven pulse-interval-modulated inductive-coupling transmitter. The fully digital, and current-driven architecture uses zero- $V_{\text {th}}$ transistors, which enables low voltage operation and a small footprint, even in a cost-competitive legacy CMOS. This enables converterless self-powered operation using a bio fuel cell, which is ideal for disposable healthcare applications. To verify the effectiveness of the proposed platform, a test chip was fabricated using 0.25- $\mu \text{m}$ CMOS technology. The experimental results successfully demonstrate operation with a 0.23-V supply, which is the lowest supply voltage reported for proximity transmitters. A self-powered biosensing operation using organic bio fuel cells was also successfully demonstrated. In addition, an asynchronous inductive-coupling receiver and an off-chip inductor for performance improvement were successfully demonstrated. [ABSTRACT FROM AUTHOR]