A 0.063-mm<sup>2</sup> 1.75-nW Biofuel Cell-Input Biosensing/Data-Storing System with 5.5-GHz Wireless Backscatter Data-Readout in 65-nm CMOS for Self-Powered Smart Contact Lenses
Akiyoshi Tanaka, Guowei Chen, Kiichi Niitsu
Abstract
This paper proposes a 1.75-nW continuous tear-glucose monitoring/data-storing IC using 5.5-GHz wireless backscatter data-readout for self-powered Smart Contact Lenses (SCL). It consists of the passive communication block using intermediate interference modulation, a self-controlled dual-oscillator-based analog to digital converter, and 8×8-bit shift-register-based memory. This work enabled stand-alone longterm sensing with on-chip data storage. The 0.063 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> chip implemented in 65-nm CMOS successfully demonstrated the correct operation of the data-storing/burst-read-out system for SCLs 4 cm away from the 15 dBm 5.5 GHz transmitter.