Capillary flow in sacrificially etched nanochannels
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Published on: February 5, 2020
Mark N Hamblin1, Aaron R Hawkins, Dallin Murray
1Department of Electrical and Computer Engineering, Brigham Young University, Provo, Utah 84602, USA.
Abstract:
Planar nanochannels are fabricated using sacrificial etching technology with sacrificial cores consisting of aluminum, chromium, and germanium, with heights ranging from 18 to 98 nm. Transient filling via capillary action is compared against the Washburn equation [E. W. Washburn, Phys. Rev. 17, 273 (1921)], showing experimental filling speeds significantly lower than classical continuum theory predicts. Departure from theory is expressed in terms of a varying dynamic contact angle, reaching values as high as 83° in channels with heights of 18 nm. The dynamic contact angle varies significantly from the macroscopic contact angle and increases with decreasing channel dimensions.

