Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 31824
Study on the Characteristics of the Measurement System for pH Array Sensors

Authors: Jung-Chuan Chou, Wei-Lun Hsia


A measurement system for pH array sensors is introduced to increase accuracy, and decrease non-ideal effects successfully. An array readout circuit reads eight potentiometric signals at the same time, and obtains an average value. The deviation value or the extreme value is counteracted and the output voltage is a relatively stable value. The errors of measuring pH buffer solutions are decreased obviously with this measurement system, and the non-ideal effects, drift and hysteresis, are lowered to 1.638mV/hr and 1.118mV, respectively. The efficiency and stability are better than single sensor. The whole sensing characteristics are improved.

Keywords: Array sensors, measurement system, non-ideal effects, pH sensor, readout circuit.

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1525


[1] P. Bergveld, "Development of an Ion sensitive solid-state device for neurophysiological measurements", IEEE Transactions on Biomedical Engineering, BME-17, pp. 70-71, 1970.
[2] J. Van Der Spiegel, I. Lauks, P. Chan, and D. Babic, "The extended gate chemical sensitive field effect transistor as multi-species microprobe", Sensors and Actuators B, vol. 4, pp. 291-298, 1983.
[3] A. Fog, and R. Buck, "Electronic semiconducting oxides as pH sensors", Sensors and Actuators, vol. 5, pp. 137-146, 1984.
[4] J. C. Chou, C. W. Chen, and P. L. Chou, "Fabrication of ruthenium oxide thin film and response characteristic for hydrogen ion," Proceedings for Annual Meeting of Physical Society of The Republic of China, vol. 29, PB-23, p. 256, 2007.
[5] L. Bousse, H. H. Van Den Vlekkert, and N. F. De Rooij, "Hysteresis in Al2O3-gate ISFETs", Sensors and Actuators B, vol. 2, pp. 181-183, 1990.
[6] P. Hein, and P. Egger, "Drift behaviour of ISFETs with Si3N4-SiO2 Gate Insulator", Sensors and Actuators B, vol. 13, pp. 655-656, 1993.
[7] L. T. Yin, J. C. Chou, W. Y. Chung, T. P. Sun, and S. K. Hsiung, "Separate structure extended gate H+-Ion sensitive field effect transistor on a glass substrate", Sensors and Actuators B, vol. 71, pp.106-111, 2000.
[8] Z. Yule, Z. Shouan, and L. Tao, "Drift characteristic of pH-ISFET output", Chinese Journal of Semiconductors, vol. 12, no. 15, pp. 838-843, 1994.
[9] L. Bousse, S. Mostarshed, B. Van Der Schoot, and N. F. De Rooij, "Comparison of the hysteresis of Ta2O5 and Si3N4 pH-sensing insulators", Sensors and Actuators B, vol. 17, pp. 157-164, 1994.
[10] S. Jamasb, S. D. Collins, and R. L. Smith, "A physical model for drift in pH ISFETs", Sensors and Actuators B, vol. 49, no. 1/2, pp. 146-155, 1998.
[11] S. Jamasb, S. D. Collins, and R. L. Smith, "A physical model for threshold voltage instability in Si3N4-Gate H+-sensitive FET-s (pH ISFET-s)", IEEE Transactions on Electron Devices, vol. 45, no. 6, pp. 1239-1245, 1998.
[12] J. L. Chiang, S. S. Jan, J. C. Chou, and Y. C. Chen, "Study on the temperature effect, hysteresis and drift of pH-ISFET devices based on amorphous tungsten oxide", Sensors and Actuators B, vol. 76, pp. 624-628, 2001.
[13] J. C. Chou, and Y. F. Wang, "Preparation and study on the drift and hysteresis properties of the tin oxide gate ISFET by the sol-gel method", Sensors and Actuators B, vol. 86, pp. 58-62, 2002.
[14] Y. H. Liao, and J. C. Chou, "Study on the nonideal characteristics of the extended gate field effect transistor based on the ruthenium nitride sensing membrane", Proceedings of the 3rd Asia-Pacific Conference of the Transducers and Micro-Nano Technology, Singapore, 4 pages (disk), 2006.
[15] T. Matsuo, and M. Esashi, "Method of ISFET fabrication", Sensors and Actuators, vol. 1, pp. 77-96, 1981.
[16] J. C. Chou, and C. N. Hsiao, "Drift behavior of ISFETs with a-Si:H-SiO2 gate insulator", Materials Chemistry and Physics, vol. 63, pp. 270-273, 2000.
[17] Y. L. Chin, J. C. Chou, Z. C. Lei, T. P. Sun, W. Y. Chung, and S. K. Hsiung, "Titanium nitride membrane application to extended gate field effect transistor pH sensor using VLSI technology", Japanese Journal of Applied Physics, vol. 40, pp. 6135-6311, 2001.