Droplet-Driven Self-Propelled Devices Fabricated by a Femtosecond Laser

Abstract

Self-propelled autonomous devices have broad application prospects in energy conservation, environmental protection, and biomedical engineering. Nevertheless, the driving force always consumes external energy or special chemicals. Here, a novel and green droplet-driven device (DDD) consisting of superhydrophilic triangles on a superhydrophobic plate is processed only by a femtosecond laser. The water droplet flows into water along the superhydrophilic channel and forms a jet to provide driving force for the DDD, whose strength can be manipulated by changing the point angle of the triangle and the volume of the droplet. By fabricating multiple or special channels, the DDD can translate and rotate along the designed track and even carry objects. This provides a new route for the fabrication of green self-propelled autonomous devices and their applications in the fields of intelligent systems and environmental protection.

Spontaneous Directional Transportation Surface of Water Droplet and Gas Bubble: A Review

“…In recent years, fluid transportation has gradually gained attention because of the development of precision medicine, micro-devices, and green energy collection. Researchers found that surfaces for water and gas transportation had numerous applications such as fog collection, heat transfer, drug transportation, and so on [1][2][3][4][5][6][7]. However, when a water droplet touches a solid surface, it will perform some indeterminate behaviors, such as impacting, jumping, trapping, and spreading.…”