TY - CHAP
T1 - An Integrated Circuit for Galvanostatic Electrodeposition of on-chip Electrochemical Sensors
AU - Li, Minghao
AU - Gill, Atal A.S.
AU - Vanhoestenberghe, Anne
AU - Ghoreishizadeh, Sara S.
N1 - Funding Information:
The authors thank Dr. Kerim Ture for designing the electrode test chip and helping with the tape out of this IC.
Publisher Copyright:
© 2022 IEEE.
PY - 2022
Y1 - 2022
N2 - This paper presents the design of an integrated circuit (IC) for (i) galvanostatic deposition of sensor layers on the on-chip pads, which serve as the sensor's base layer, and (ii) amperometric readout of electrochemical sensors. The system consists of three main circuit blocks: the electrochemical cell including a 4×4 electrode array, two Beta-multiplier based current generators and one pA-size current generator for galvanostatic electrodeposition, and a switch-capacitor based amperometric readout circuit for sensor current measurement. The circuits are designed and simulated in a 180-nm CMOS process. The three current reference circuits generate a stable current from 7.2 pA to 88 µA with low process, power supply voltage and temperature (PVT) sensitivity. The pA-size current generator has a temperature coefficient of 517.8 ppm/°C on average (across corners) in the range of 0 to 60°C. The line regulation is 4.4 %/V over a supply voltage range of 0.8-3 V. The feasibility of galvanostatic deposition on on-chip pads is validated by applying a fixed current of 300 nA to electrochemically deposit a gold layer on top of electrodes with nickel/zinc as the adhesive layer for gold. Successful deposition of gold was confirmed using optical microscope images of the on-chip electrodes.
AB - This paper presents the design of an integrated circuit (IC) for (i) galvanostatic deposition of sensor layers on the on-chip pads, which serve as the sensor's base layer, and (ii) amperometric readout of electrochemical sensors. The system consists of three main circuit blocks: the electrochemical cell including a 4×4 electrode array, two Beta-multiplier based current generators and one pA-size current generator for galvanostatic electrodeposition, and a switch-capacitor based amperometric readout circuit for sensor current measurement. The circuits are designed and simulated in a 180-nm CMOS process. The three current reference circuits generate a stable current from 7.2 pA to 88 µA with low process, power supply voltage and temperature (PVT) sensitivity. The pA-size current generator has a temperature coefficient of 517.8 ppm/°C on average (across corners) in the range of 0 to 60°C. The line regulation is 4.4 %/V over a supply voltage range of 0.8-3 V. The feasibility of galvanostatic deposition on on-chip pads is validated by applying a fixed current of 300 nA to electrochemically deposit a gold layer on top of electrodes with nickel/zinc as the adhesive layer for gold. Successful deposition of gold was confirmed using optical microscope images of the on-chip electrodes.
KW - biosensor array
KW - complementary metal-oxide semiconductor (CMOS)
KW - current reference
KW - electrochemical sensor
KW - potentiostat
KW - sensor fabrication
KW - subthreshold region
UR - http://www.scopus.com/inward/record.url?scp=85145359535&partnerID=8YFLogxK
U2 - 10.1109/ICECS202256217.2022.9970881
DO - 10.1109/ICECS202256217.2022.9970881
M3 - Conference paper
AN - SCOPUS:85145359535
T3 - ICECS 2022 - 29th IEEE International Conference on Electronics, Circuits and Systems, Proceedings
BT - ICECS 2022 - 29th IEEE International Conference on Electronics, Circuits and Systems, Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 29th IEEE International Conference on Electronics, Circuits and Systems, ICECS 2022
Y2 - 24 October 2022 through 26 October 2022
ER -