title: Droplet Motion on a Shape Gradient Surface.
abstract: We demonstrate a facile method to induce water droplet motion on an wedge-shaped superhydrophobic copper surface combining with a poly(dimethylsiloxane) (PDMS) oil layer on it. The unbalanced interfacial tension from the shape gradient offers the actuating force. The superhydrophobicity critically eliminates the droplet contact line pinning and the slippery PDMS oil layer lubricates the droplet motion, which makes the droplet move easily. The maximum velocity and furthest position of droplet motion were recorded and found to be influenced by the gradient angle. The mechanism of droplet motion on the shape gradient surface is systematically discussed, and the theoretical model analysis is well matched with the experimental results.
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, People's Republic of China.
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, People's Republic of China.
authors.forename: Jiang
authors.identifier: 0000-0002-9947-6193
authors.initials: J
authors.lastname: Cheng
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, People's Republic of China.
authors.forename: Cailong
authors.initials: C
authors.lastname: Zhou
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, People's Republic of China.
authors.forename: Haiting
authors.initials: H
authors.lastname: Xing
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, People's Republic of China.
authors.forename: Xiufang
authors.identifier: 0000-0001-5071-8940
authors.initials: X
authors.lastname: Wen
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, People's Republic of China.
authors.forename: Pihui
authors.initials: P
authors.lastname: Pi
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510640, People's Republic of China.
authors.forename: Shouping
authors.initials: S
authors.lastname: Xu