Carnivorous plants inspired shape-morphing slippery surfaces

Abstract

Carnivorous plants, for instance, Dionaea muscipula and Nepenthes pitcher plant, inspired the innovation of advanced stimuli-responsive actuators and lubricant-infused slippery surfaces, respectively. However, hybrid bionic devices that combine the active and passive prey trapping capabilities of the two kinds of carnivorous plants remain a challenge. Herein, we report a moisture responsive shape-morphing slippery surface that enables both moisture responsive shape-morphing and oil-lubricated water repellency for simultaneous active- and passive-droplet manipulation. The moisture deformable slippery surface is prepared by creating biomimetic microstructures on graphene oxide (GO) membrane via femtosecond laser direct writing and subsequent lubricating with a thin layer of oil on the laser structured reduced GO (LRGO) surface. The integration of a lubricant-infused slippery surface with an LRGO/GO bilayer actuator endows the actuator with droplet sliding ability and promotes the moisture deformation performance due to oil-enhanced water repellency of the inert layer (LRGO). Based on the shape-morphing slippery surface, we prepared a series of proof-of-concept actuators, including a moisture-response Dionaea muscipula actuator, a smart frog tongue, and a smart flower, demonstrating their versatility for active/passive trapping, droplet manipulation, and sensing.

Keywords

• femtosecond laser fabrication
• graphene oxide
• moisture responsive actuators
• slippery surface
• bionic devices