Micro-viscometer based on electrowetting on dielectric
Journal
Electrochimica Acta
Journal Volume
52
Journal Issue
8 SPEC. ISS.
Pages
2876-2883
Date Issued
2007
Date
2007
Author(s)
Abstract
A viscometer used to measure the viscosity of 10 μl of a liquid, must be miniaturized down, and the liquid velocity gradient in the channel used to determine the viscosity coefficient. Two major factors that affect the liquid velocity are the mechanical forces exerted by the mechanical motors and electromagnetic forces. In this study, electrowetting on dielectric (EWOD) is adopted to drive liquids. Variously sized electrodes on a chip, and two shapes of channel are employed to measure the velocity gradient to determine the viscosity coefficient. The device is fabricated by microelectromechanical system (MEMS) technology. The dielectric layer used in EWOD has a high dielectric constant, BST (Ba0.7Sr0.3TiO3), to reduce the required applied voltage; its surface is coated with hydrophobic polymer, polytetrafluoro-ethylene (PTFE, Teflon® AF DuPont). Experimental results demonstrate that liquids can be pulled at 660 μm/s in linear channels by applying a voltage of 15 V. © 2006 Elsevier Ltd. All rights reserved.
Subjects
Electrowetting (EW); Electrowetting on dielectric (EWOD); Micro electromechanic system (MEMS); Microfluid; Viscometer
SDGs
Other Subjects
Dielectric materials; Fluidics; Microelectromechanical devices; Viscosity; Wetting; Electrowetting (EW); Electrowetting on dielectric (EWOD); Microfluidics; Viscometers
Type
journal article
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