Diversity of animals and their adaptability to the environment have provided a reference for the development of robot technology. Based on the various capabilities of creatures in the nature, researchers have developed a wide range of bionic robots. These robots have broad application prospects in the fields of scientific detection and environmental monitoring owing to their unique functions and motions, which have garnered an increasing amount of attention from the researchers.

A miniature robot capable of efficiently moving on the water surface can complete various tasks in the ocean, river, or microfluidic surface, and has been widely investigated in the past decades. However, improving the efficiency, long-time and long-distance movement of such robots continues to be a challenge.

In nature, water striders are interesting insects that can float, glide, and jump freely on the water surface. Their legs have micro- and nano-cilia structures, which make them superhydrophobic, leading to their efficient movement at the air/water interface.

Recently, inspired by the superhydrophobicity of the water strider, researchers from Shenyang Institute of Automation, Chinese Academy of Sciences (SIACAS) have prepared a graphene/polydimethylsiloxane (PDMS) composite materials which exhibit excellent superhydrophobic and photothermal properties. The developed material exhibits good machinability and can be easily cut into a variety of small-scale complex structures and different shapes of robots with superhydrophobic and photothermal properties.

A water strider-like miniature robot is fabricated thereafter. The robots can glide and rotate at the air/water interface under the action of infrared light. The robots can also realize a fast reciprocating and roll-over jumping motion under the control of magnet. The experiments exhibit good infrared light driving performance and magnetic controllability of the strider-like miniature robots. This work not only presents a method to prepare superhydrophobic miniature robots based on graphene, but also provides a reference for the development of multifunctional miniature robots, and further promotes the application of miniature robots in liquid detection and oil recovery.

This study is published on Chemical Engineering Journal 422 (2021):129394.