Switchable Wettability Of Deformation Behavior And Functional Mechanism Driven By Oil

Since the birth of organisms on the earth,under the law of survival of the fittest in nature,in order to meet their own needs and adapt to the development of the environment,some organisms have evolved unique wettability on their surfaces to ensure their survival.Recently,due to the wide application of its special wettability intelligent bionic materials in daily fields,it has promoted countless researchers to conduct in-depth investigations and made breakthroughs.Furthermore,a single unique wettability can no longer meet people's needs for a better life,so intelligent bionic materials with adjustable wettability that respond to external stimuli are more and more favored.So far,adjustable wettability transition materials have been applied in various fields and have achieved gratifying results.Commonly used wettability transitions mainly focus on reversible changes in chemical composition and microstructure under external stimuli.However,chemical composition changes have problems such as complex chemical processing,slow response,environmental pollution,and limited life span,which will restrict the wetting of the transition material Further development.Based on the above analysis,wetting materials that respond intelligently to structural changes will become the trend of future development.Inspired by nature's unique wettability of the biological surface microstructure,this paper prepared a PDMS superhydrophobic surface with tensile properties,successfully completed droplet bounce experiments,droplet transfer experiments,and single-sided laser etching of the PDMS structure Janus film,using its oil absorption swelling and wettability difference to bend,successfully manufactured a soft robot capable of directional motion,which provides a reference for applications in fog collection,droplet/fluid manipulation,intelligent soft robots and other related fields.The main research conclusions are as follows:Through a simple one-step laser etching method,we have successfully fabricated a PDMS superhydrophobic surface with tensile properties.Under simple mechanical stretching,the surface microstructure of the sample undergoes a reversible transformation,which causes the PDMS surface to change from super-hydrophobic low-adhesion to hydrophobic high-adhesion.We explored the effects of laser power,laser interval,and sample thickness on the tensile wettability of the PDMS surface,and found the best parameters,and successfully completed droplet bounce and droplet transfer experiments.Laser processing the PDMS surface on one side to construct Janus films with different wettability on both sides of the film.Taking advantage of the superhydrophobic,super-lipophilic and oil-absorbing swelling characteristics of the film,we dripped oil to deform and bend the PDMS film,and explored the relationship between the degree of bending and the volume of the dripped oil,the type of oil,and the content of graphene.At the same time,according to the concept of asymmetrical structure and unbalanced force,we mechanically cut the two sides of the membrane into different shapes to explore the movement of the PDMS membrane caused by the dripping of oil.The results show that the PDMS film undergoes directional movement after mechanical cutting,and its movement speed is related to the cutting shape and the ambient temperature.This research provides some references for promoting the development of intelligent soft robot movement.