Authors: N. Vourdas, V.N. Stathopoulos
Affilation: Technological Educational Institute of Sterea Ellada, Greece
Pages: 220 - 223
Keywords: droplet mobility, droplet actuation, valving
Synthesis of surfaces with special tunable wettability as well as transitions between various wetting states are now intensively studied both for understanding wetting principles as well as for practical applications. Herein we present an alternative method to dynamically actuate droplets and manipulate their mobility on porous surfaces by means of backpressure control. Porous media have been formed and chemically modified to render them hydrophobic and superhydrophobic. Sliding angle of various volume water droplets was measured for a wide range of backpressure values. The sliding angle, e.g. for a 50 μl droplet decreases from 22o to 0o when the backpressure increases to 0.800 bar. Experimental results for both small droplets as well as for large droplets are followed using a modified respective model. Application of our approach is demonstrated on a fluidic for valving applications.