title: Wetting Phenomena on (Gradient) Wrinkle Substrates.
abstract: We characterize the wetting behavior of nanostructured wrinkle and gradient wrinkle substrates. Different contact angles on both sides of a water droplet after deposition on a gradient sample induce the self-propelled motion of the liquid toward smaller wrinkle dimensions. The droplet motion is self-limited by the contact angles balancing out. Because of the correlation between droplet motion and contact angles, we investigate the wetting behavior of wrinkle substrates with constant dimensions (wavelengths of 400-1200 nm). Contact angles of water droplets on those substrates increase with increasing dimensions of the underlying substrate. The results are independent of the two measurement directions, parallel and perpendicular to the longitudinal axis of the nanostructure. The presented findings may be considered for designing microfluidic or related devices and initiate ideas for the development of further wrinkle applications.
authors: Fraunhofer-Institut für Angewandte Polymerforschung IAP, D-14476 Potsdam-Golm, Germany.
authors: Stephanie
authors: S
authors: Hiltl
authors: Fraunhofer-Institut für Angewandte Polymerforschung IAP, D-14476 Potsdam-Golm, Germany.|Lehrstuhl für Polymermaterialien und Polymertechnologien, Universität Potsdam , D-14476 Potsdam-Golm, Germany.
authors: Alexander
authors: A
authors: Böker