Relationship Between Contact Angle Hysteresis and Electrowetting On Dielectric

Tuesday, November 9, 2010: 3:55 PM
Canyon A (Hilton)
Rohini Gupta and Joelle Frechette, Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD

The effect of contact angle hysteresis on the electrowetting response is not well-understood. We have developed materials for EWOD with variable contact angle hysteresis (between 1-25o). Using these materials we have investigated the effect of the contact angle hysteresis on the spreading of the fluid drop with applied potential. Our results demonstrate that even a small amount of contact angle hysteresis (5o) will alter the electrowetting performance. We have also found a linear relationship between the electrowetting hysteresis and the contact angle hysteresis, with the electrowetting hysteresis being half of the contact angle hysteresis. We discuss this relationship in the context of the forces acting on the triple contact line.

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See more of this Session: Fundamentals of Interfacial Phenomena III
See more of this Group/Topical: Engineering Sciences and Fundamentals