本論文提出一個應用於生醫感測器的伏安式恆電位儀，此電路可量測電化學反應所產生之氧化還原電流。藉由氧化還原偵測電路來控制氧化還原電位並判斷正在進行之電化學反應，而電流傳輸器架構可穩定感測器之電位。另外透過電流鏡提升感測電流範圍，並且將複製之感測電流由電流時間轉換器轉換為時域訊號，以便後端電路處理。運用於三電極系統之控制放大器電路則以掃描電壓來進行循環伏安法量測，本伏安式恆電位儀以達到高靈敏度、低功耗、小面積為設計目的。
此伏安式恆電位儀以台灣積體電路公司0.18微米一層多晶矽六層金屬導線互補式金屬氧化物半導體製程實現，晶片面積則佔0.49 mm2左右。量測結果顯示，在電源電壓1.8 V的條件下，整體功率消耗為1.314 mW，可量測之電流範圍從15 μA到1500 μA，其線性回歸以最小平方法分析變異量可得到誤差小於0.3 %，以掃描電壓0.3 V到1.1 V的循環伏安法量測時，可得誤差小於0.7 %，並且得到以電化學方式量測褪黑激素的結果。

This thesis presents a voltammetry potentiostat for biomedical sensors. The proposed circuit can measure redox current generated by electrochemical reactions. The redox detection circuit is realized to control the redox voltage and determine redox reactions, and the current conveyor is adopted to maintain a stable potential at sensor terminal. The range of sensor current is improved by the implemented current mirror. Followed by the current-to-time converter, the mirrored image of sensor current is transformed into time domain signal for back-end circuit processing. The control amplifier circuit with scanning redox voltage is adopted in the three-electrode system for cyclic voltammetry measurement. The proposed voltammetry potentiostat is designed to achieve high sensitivity, low power and small area.
This proposed voltammetry potentiostat is implemented in TSMC 0.18-μm 1P6M CMOS technology and the chip area is about 0.49 mm2. It consumes 1.314 mW from 1.8 V supply voltage. The fabricated IC measures the sensor current from 15 μA to 1500 μA with less than 0.3 % error. In cyclic voltammetry measurement, the proposed circuit has less than 0.7 % error with sweep redox voltage from 0.3 V to 1.1 V, and the electrochemical measurement results of melatonin have been acquired.

[1] M. Stanacevic, K. Murari, G. Cauwenberghs, and N. V. Thakor, “16-channel wide-range VLSI potentiostat array,” in Proc. IEEE Int. Workshop Biomed. Circuits and Syst., Dec. 2004, pp. SI/7/INV/17–20.
[2] K. Murari, M. Stanacevic, G. Cauwenberghs, and N. V. Thakor, “Wide-range, picoampere-sensitivity multichannel VLSI potentiostat for neurotransmitter sensing,” in Proc. Annu. Int. Conf. IEEE Int. Eng. Med. Biol. Soc., Sept. 2004, pp. 4063–4066.
[3] P. W. Cheung, D. G. Fleming, W. H. Ko, and M. R. Neuman, Eds., Theory, Design, and Biomedical Applications of Solid State Chemical Sensors., West Palm Beach, FL: CRC Press, 1978, pp. 190–205.
[4] C. H. Ahn, J. W. Choi, G. Beaucage, J. H. Nevin, J. B. Lee, A. Puntambekar, and J. Y. Lee, “Disposable smart lab on a chip for point-of-care clinical diagnostics,” Proc. IEEE, vol. 92, no. 1, pp. 154–173, Jan. 2004.
[5] G. L. Coté, R. M. Lec, and M.V. Pishko, “Emerging biomedical sensing technologies and their applications,” IEEE Sensors J., vol. 3, pp. 251–266, June 2003.
[6] L. Clark Jr. and C. Lyons, Ann. NY Acad. Sci., vol. 120, pp. 29–45, Oct. 1962.
[7] R. F. B. Turner, D. J. Harrison, H. P. Baltes, “A CMOS potentiostat for amperometric chemical sensors,” IEEE J. Solid-State Circuits, vol. 22, pp. 473–478, June 1987.
[8] R. G. Kakerow, H. Kappert, E. Spiegel, and Y. Manoli, “Low-power single-chip CMOS potentiostat,” in Proc. IEEE Int. Conf. Solid-State Sensors and Actuators, June 1995, pp. 142–145.
[9] M. Breten, T. Lehmann, and E. Braun, “Integrating data converters for picoampere currents from electrochemical transducers,” in Proc. IEEE Int. Symp. Circuits Syst., May 2000, pp. 709–712.
[10] A. Bandyopadhyay, G. Mulliken, G. Cauwenberghs, and N. V. Thakor, “VLSI potentiostat array for distributed electrochemical neural recording,” in Proc. IEEE Int. Symp. Circuits Syst., May 2002, pp. 740–743.
[11] H. S. Narula and J. G. Harris, “A time-based VLSI potentiostat for ion current measurements,” IEEE Sensors J., vol. 6, pp. 239–247, Apr. 2006.
[12] M. M. Ahmadi and G. A. Jullien, “Current-mirror based potentiostats for three-electrode amperometric electrochemical sensors,” IEEE Trans. Circuits Syst. I, Reg. Papers, vol. 56, pp. 1339–1348, July 2009.
[13] M. Stanacevic, K. Murari, A. Rege, G. Cauwenberghs, and N. V. Thakor, “VLSI potentiostat array with oversampling gain modulation for wide-range neurotransmitter sensing,” IEEE Trans. Biomed. Circuits Syst., vol. 1, pp. 63–72, Mar. 2007.
[14] S. Sutula, J. P. Cuxart, J. Gonzalo-Ruiz, F. X. Muñoz-Pascual, L. Terés, and F. Serra-Graells, “A 25-µW all-MOS potentiostatic delta-sigma ADC for smart electrochemical sensors,” IEEE Tran. Circuits Syst. I, Reg. Papers, vol. 61, pp. 671–679, Mar. 2014.
[15] G. Massicotte, M. Sawan, G. De Micheli, and S. Carrara, “Multi-electrode amperometric biosensor for neurotransmitters detection,” in Proc. IEEE Biomed. Circuits Syst. Conf., Nov. 2013, pp. 162–165.
[16] A. J. Bard and L. R. Faulkner, Electrochemical Methods Fundamentals and Applications. New York: Wiley, pp. 156–304, Dec. 2001.
[17] L. Busoni, M. Carla, and L. Lanzi, “A comparison between potentiostatic circuits with grounded work or auxiliary electrode,” Rev. Sci. Instrum., vol. 73, no. 4, pp. 1921–1923, Apr. 2002.
[18] R. Greef, “Instruments for use in electrode process research,” J. Phys. E, Sci. Instrum., vol. 11, no. 1, pp. 1–12, Jan. 1978.
[19] J. Zhang, N. Trombly, and A. Mason, “A low noise readout circuit for integrated electrochemical biosensor arrays,” in Proc. IEEE Sensors, Oct. 2004, pp. 24–27.
[20] R. Doelling, “Potentiostats,” in Bank Elektronik Application Note, 2nd ed. Clausthal-Zellerfeld, Germany: Bank Elektroni–Intelligent Controls GmbH, Mar. 2000.
[21] P. S. Manhas, K. Pal, S. Sharma, L. K. Mangotra, and K. K. S. Jamwal, “New low-voltage class AB current conveyor II for analog applications,” Indian J. Pure Ap. Phy., vol. 47, pp. 306–309, Apr. 2009.
[22] N. Tripathi, N. Saxena, and S. Soni, “Design of an amplifier through second generation current conveyor,” Int. J. Eng. Trends Tech. vol. 4, pp. 1325–1330, May 2013.
[23] Alldatasheet.com, Electronic Components Datasheet Search. [Online]. Available: http://www.alldatasheet.com/view.jsp?Searchword=LM317
[24] C. Y. Huang, “Design of a voltammetry potentiostat for biochemical sensors,” Analog Integr. Circ. S., vol. 67, pp. 375–381, June 2011.
[25] W. J. Liu, M. H. Yu, B.D. Liu, and C. L. Wei, “Automatic current range detection for biochemical sensor,” in Proc. IEEE Int. Conf. SoC Des., Nov. 2014, pp. 196–197.
[26] B. Razavi, Design of Analog CMOS Integrated Circuits. New York: McGraw-Hill, 2001, pp. 100–360.
[27] D. A. Johns and K. Martin, Analog Integrated Circuit Design. New York: Wiley, 1997, pp. 82–329.