title: Direct measurement of friction of a fluctuating contact line.
abstract: We report a direct measurement of the friction coefficient of a fluctuating (and slipping) contact line using a thin vertical glass fiber of diameter d with one end glued onto a cantilever beam and the other end touching a liquid-air interface. By measuring the broadening of the resonant peak of the cantilever system with varying liquid viscosity η, we find the friction coefficient of the contact line has a universal form, ξ(c)≃0.8πdη, independent of the liquid-solid contact angle. The obtained scaling law is further supported by the numerical simulation based on the phase field model under the generalized Navier boundary conditions.
authors.affiliation: Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Shuo
authors.initials: S
authors.lastname: Guo
authors.forename: Min
authors.initials: M
authors.lastname: Gao
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Xiong
authors.forename: Yong Jian
authors.initials: YJ
authors.lastname: Wang
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Sheng
authors.forename: Penger
authors.initials: P
authors.lastname: Tong