title: Adhesion forces and contact angles of water strider legs.
abstract: This study investigated the adhesion (pull-off) force and contact angles of a water strider's leg. During hydrostatic experiments, the adhesion force was found to be 2 dyn. The image of a cross section of a live leg contacted with a deformed water surface provided the contact angle of 168.8 degrees . A numerical scheme was proposed to determine the water surface on a groove wall of a seta. The results showed that the asperities of a seta are almost wetted, and the fraction of the wetted projection area was 0.69. Thus, the contact angle of a seta was 124.8 degrees .
authors.affiliation: Department of Mechanical Engineering, Center for Micro/Nano Science and Technology, and Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Pal Jen
authors.initials: PJ
authors.lastname: Wei
authors.forename: Sheng Chao
authors.initials: SC
authors.lastname: Chen
authors.forename: Jen Fin
authors.initials: JF
authors.lastname: Lin