An Independent, Temperature-Controllable Microelectrode Array

• Published in: Analytical chemistry (Washington) 2004-03, Vol.76 (5), p.1537-1543
• Main Authors: Yang, Haesik, Choi, Chang Auck, Chung, Kwang Hyo, Jun, Chi-Hoon, Kim, Youn Tae
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Biochemistry; Chemistry; Electrodes; Exact sciences and technology; General, instrumentation; Microbiology; Temperature
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac035270p

Rapid, localized temperature control and negligible power consumption are key requisites for realizing effective parallel and sequential processing in the miniaturized, integrated biomedical microdevices where temperature-dependent biochemical reactions and fluid flow occur. In this study, an independent, temperature-controllable microelectrode array, with excellent temperature control rates and minimal power consumption, has been developed using microelectromechanical systems technology. The microfabricated array consists of Pt microelectrodes (100-μm diameter), with n-doped polysilicon microheaters (1.4-kΩ resistance), and vacuum-sealed cavities of depth 6.2 μm and diameter 200 μm. The thermal characteristics of each microelectrode were evaluated electrochemically through surface temperature measurements. The large heater power coefficient (2.1 ± 0.1 °C mW-1) and the short heating and cooling times (less than 0.2 s for T 0.95) are consequences of the vacuum-sealed cavities, which facilitate good thermal isolation and low thermal mass. The temperature of each microelectrode is independently controlled by a dedicated microheater, without thermally influencing the adjacent microelectrodes significantly.