Wireless powered implantable bio-sensor tag system-on-chip for continuous glucose monitoring

An implantable passive radio frequency identification (RFID) sensor tag system-on-chip (SoC) for glucose monitoring is developed in this paper. A high frequency RFID tag, a bio-sensor interface, as well as the electrodes are included in this chip. The signal of blood sugar level from the bio-sensor is detected and converted into digital data, and then the data is encrypted and transmitted to an RFID reader on top of the skin. To measure the weak current signals, a current readout circuit, a current splitter, an ADC and a potentiostat are designed in the chip. Correlated double sample (CDS) technology is used in the readout circuit to reduce the 1/f noise and the op-amp´s offset. The chip is taped out in SMIC 0.13 μm CMOS process. Simulation results show that the system can measure weak current signals in the range of 10 fA-100 pA.