LAUSR

This paper presents a self-powered wireless physiochemical sensing system for monitoring of glucose or lactate in bodily fluids. The biosensor chip consists of a duty-cycled biofuel cell (BFC) maximum power point tracker analog front end, a passive $\Delta \!\Sigma $ analog-to-digital converter (ADC), an RF power oscillator transmitter using a 1-cm external loop antenna, digital data storage, and timing and clock generation circuitries, all designed to operate from the dynamic 0.3-V BFC output voltage. The biosensor chip, implemented in 65-nm CMOS and exclusively powered via an enzymatic BFC, can successfully detect changes in glucose/lactate concentration between 2.5 and 15 mM, for the first demonstration of an integrated self-powered chemical biosensing system with digital wireless readout. The biosensor consumes an average power of 1.15 $\mu \text{W}$ .