Combining water-repelling superhydrophobic surfaces with water-loving hydrophilic surfaces allows scientists and engineers to manipulate common fluids. Here a hydrophilic track surrounded by a superhydrophobic background collects and distributes drops of dyed water. The wetting characteristics of the surface combined with surface tension in the liquid drives the flow. No pumping or power input is necessary. This kind of manipulation of droplets can be especially useful in biomedical applications where fast-acting, low-cost devices could be used to diagnose diseases or measure blood glucose levels. (Image credit: A. Ghosh et al., via NSF; see also source video)
Manipulating Fluids
