@inproceedings { chu_micromachine, title = {A micromachined Kelvin probe for surface potential measurements in microfluidic channels and solid-state applications}, journal = {TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664)}, volume = {vol.1}, year = {2003}, pages = {384-7}, publisher = {IEEE}, organization = {IEEE}, type = {inproceedings}, address = {Boston, MA, USA}, abstract = {This paper reports on a micromachined Kelvin probe structure with integrated scanning tip and dither actuation mechanism. It is fabricated by a modified micro electro-discharge machining process which allows electrical isolation within the micromachined structure using epoxy plugs. 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 \≈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 SiO2 layer on a Si substrate, showing it to be suitable for monitoring microelectronics manufacturing processes}, keywords = {contact potential,discharges (electric),electric actuators,microfluidics,pH,silicon compounds,surface potential}, URL = {http://dx.doi.org/10.1109/SENSOR.2003.1215334}, author = { Chu, L.L. and Takahata, K. and Selvaganapathy, P. and Shohet, J.L. and Gianchandani, Y.B.} }