Dielectrophoresis Response and Manipulation of Silica and its Application to Micro/Nanosensors

Abstract

In this paper, silica microspheres and several novel μm scale DEP (dielectrophoresis) micro electrode array chips were prepared. A DEP experimental system was assembled to investigate the the DEP response of silica microspheres and micrometer particles. The effects of pattern of electrodes and frequency of AC field on the manipulation of silica microspheres were analyzed. The results showed that silica microspheres were manipulated by negative DEP (nDEP) in all types of electrodes, the position of silica microspheres in the electrodes changed when the frequency was changed and the phenomenon of nDEP was more obvious at higher frequency. A gas sensor was fabricated by dielectrophoretically assembling SiO2micrometer particles. The sensor showed good response to SO2and NH3gas. The measurement results confirmed DEP could be a quicker method for constructing gas sensor.