Elasticity-driven droplet movement on a microbeam with gradient stiffness: a biomimetic self-propelling mechanism.
Directional movement of liquid droplets is of significance not only for certain physiological processes in nature but also for design of some microfluidic devices. In this study, we report a novel way to drive directional movement of liquid droplets on a microbeam with a varying or gradient stiffness. We use the energy method to theoretically analyze the interaction between a droplet and the elastic microbeam. The system tends to have the minimum potential energy when the droplet moves to the softer end of the beam. Therefore, a gradient change of the bending stiffness may be utilized to help the directional motion of droplets. Similarly, one can also drive droplets to move in a designed direction by varying the cross sectional geometry of the beam. Finally, some possible applications of this self-propelling mechanism are suggested.
Zheng
Xiu-Peng
XP
FML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
Zhao
Hong-Ping
HP
Gao
Ling-Tian
LT
Liu
Jian-Lin
JL
Yu
Shou-Wen
SW
Feng
Xi-Qiao
XQ
D032701:Biomimetics; D002621:Chemistry / Q000379:methods; D004548:Elasticity; D004867:Equipment Design; D004864:Equipment and Supplies; D008422:Materials Testing; D044085:Microfluidics; D015233:Models, Statistical; D008962:Models, Theoretical; D009038:Motion; D009068:Movement; D011312:Pressure; D013499:Surface Properties