A Micromachined Kelvin Probe With Integrated Actuator for Microfluidic and Solid-State Applications

TitleA Micromachined Kelvin Probe With Integrated Actuator for Microfluidic and Solid-State Applications
Publication TypeJournal Article
Year of Publication2005
AuthorsChu, L. L., K. Takahata, P. R. Selvaganapathy, Y. B. Gianchandani, and J. L. Shohet
JournalMicroelectromechanical Systems, Journal of
Pagination691 - 698
Date Publishedaug.
Keywordsaxial dithering motion, electrical isolation, electrothermal actuator, integrated actuator, Kelvin probe, microactuators, microelectrodischarge machining, microelectronics manufacturing processes contact potential, microfluidic application, microfluidics, micromachining, oxide charge, probes, process monitoring, solid-state application, surface potential, surface potential measurement, voltage measurement

This paper reports on a micromachined Kelvin probe structure with an integrated scanning tip and an integrated electrothermal actuator that provides axial dithering motion. The device is fabricated from metal foil by a modified microelectrodischarge machining process that allows electrical isolation within the device. In particular, it permits the incorporation of a wide epoxy plug that creates an insulating gap with low parasitic capacitance between the probe and the actuator. The epoxy structures are found to withstand the thermal and mechanical conditions encountered during device operation. The device is used to measure changes in the external surface potential of a parylene microfluidic channel as a function of varying pH of liquid inside the channel. A contact potential difference of$approx 6  V$is measured for a change in pH from 4 to 8 within the channel. The device is also used to map embedded charge in a thin$ SiO_2$layer on a Si substrate, showing it to be suitable for monitoring microelectronics manufacturing processes.hfillhbox[1072]


a place of mind, The University of British Columbia

Electrical and Computer Engineering
2332 Main Mall
Vancouver, BC Canada V6T 1Z4
Tel +1.604.822.2872
Fax +1.604.822.5949

Emergency Procedures | Accessibility | Contact UBC | © Copyright 2021 The University of British Columbia