Research On Microstructural Design Regulation And Intelligent Actuation Of Graphene Oxide Film

Intelligent actuators could respond to external stimuli(light,heat,electricity,humidity,magnetism,etc.)and perform corresponding operations or commands,which have broad prospects in the fields of micro-robot,information interaction and remote control.It has always been a focus for researchers to prepare intelligent actuators with excellent actuating performances through reasonable material selection and scientific structure design.In this paper,a graphene oxide film with period-gradient sectionalized structure was prepared through the simple template method.It focuses on the effects of microstructure design on the actuating performances based on the GO material with excellent comprehensive properties,and it breaks through the frequently-used comlex design concepts of composite materials or composite structures in intelligent actuators.The actuating performances were explored in the field of moisture actuation and electrostatic actuation.Combined with mechanical principles and actuating characteristics,the actuating mechanism and application prospects were further analyzed and studied.The details are as follows(1)The GO suspension was prepared by the modified Hammers’ method.The obtained GO suspension showed an excellent degree of oxidation and stripping.The content ratio of the main constituent elements O and C is 0.35 and the GO sheets are nano-sized.The grating substrate was selected as the template and a GO film with microstructure was prepared by template method through coating-evaporation.The effects of the coating thickness on the formation and microstructure construction was further studied.Due to the effects of surface tension and sheets stack,the results showed that it became easier for the complete peeling and formation of the GO film,but the difficulties of microstructure construction on the surface increased as the coating thickness increased(250 μm,500 μm,750 μm,and 1000 μm).(2)Based on the above study on structure,a bio-inspired GO film moisture actuator with period-gradient structures was designed and prepared through the template method.The moisture actuator could maintain a flat state at low relative humidity(RH≈25%)and exhibit a large-angle bending response deformation of about 1000 0 at high relative humidity(RH≈85%).And in the cyclic process between low and high relative humidity,the actuator exhibited reversible response behavior and excellent cyclic stability.Combining the characteristics of material and structure with the mechanical principles,the moisture actuating mechanism of the bio-inspired period-gradient GO film was further proposed,and a mechanical theoretical model was developed to verify and interpret the actuating mechanism in interdisciplinarity through mechanical simulation.Further combined with the actuating characteristics,the intelligent crawling movement based on the bionic mollusk and the multi-modal deformation based on the bionic plant vine were realized.(3)A sectionalized GO film electrostatic actuator was designed and prepared through the template method to achieve non-contact actuation.The electrostatic actuator could exhibit obvious macroscopic response deformation within 1s quickly triggered by static electricity,and the actuating behaviors showed the good reversible and cyclic properties.The effects of the structure design on the electrostatic actuating performances and actuating mechanism of the sectionalized GO film electrostatic actuator were further explored and proposed,and they were explained and verified by simulation analysis.Further combined with the actuating characteristics,the designated controllable electrostatic actuation of the array was realized successfully.