cutting a drop of water pinned by wire loops using a superhydrophobic surface and knife减少线的一滴水固定循环使用超疏水表面和刀.pdfVIP

Cutting a Drop of Water Pinned by Wire Loops Using a Superhydrophobic Surface and Knife 1 ´ 2 3 1 1 Ryan Yanashima , Antonio A. Garcıa *, James Aldridge , Noah Weiss , Mark A. Hayes , James H. Andrews3 1 Department of Chemistry Biochemistry, Arizona State University, Tempe, Arizona, United States of America, 2 School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona, United States of America, 3 Department of Physics and Astronomy, Youngstown State University, Youngstown, Ohio, United States of America Abstract A water drop on a superhydrophobic surface that is pinned by wire loops can be reproducibly cut without formation of satellite droplets. Drops placed on low-density polyethylene surfaces and Teflon-coated glass slides were cut with superhydrophobic knives of low-density polyethylene and treated copper or zinc sheets, respectively. Distortion of drop shape by the superhydrophobic knife enables a clean break. The driving force for droplet formation arises from the lower surface free energy for two separate drops, and it is modeled as a 2-D system. An estimate of the free energy change serves to guide when droplets will form based on the variation of drop volume, loop spacing and knife depth. Combining the cutting process with an electrofocusing driving force could enable a reproducible biomolecular separation without troubling satellite drop formation. ´ Citation: Yanashima R, Garcıa AA, Aldridge J, Weiss N, Hayes MA, et al. (2012) Cutting a Drop of Water Pinned by Wire Loops Using a Superhydrophobic Surface and Knife. PLoS ONE 7(9): e45893. doi:10.1371/journal.pone.0045893 Editor: Aristides Docoslis, Queen’s Uni