Deformation And Multi-Information Perception Of Smart Hydrogel-Based Actuating/Sensing Dual-Functional Composite Material Under External Stimuli

The use of flexible composite materials that incorporate both sensing and actuation capabilities has become an important area of research,particularly in the field of soft robotics.Smart hydrogels,as a popular type of flexible material,have been favored by researchers due to their wider functionality and richer selectivity.However,current research on smart hydrogel-based dual-function composites with both actuation and sensing capabilities is limited,and is mostly restricted to thermal actuation and pressure sensing integration,with a limited range of stimuli and sensing modes,thus limiting their application range.Therefore,the development of smart hydrogel-based dual-function composites that can actuate deformation and perceive multiple information in various stimulus environments has become a current research hotspot.In order to solve the above problems,this paper prepared an smart hydrogel based actuating/sensing dual functional composite material by embedding a flexible piezoresistive-piezoelectric dual-mode sensor with multi-information perception capability into the smart hydrogel.Using its ability to rapidly deform under ionic stimulation and multi-information perception,it achieved the purpose of real-time monitoring of its deformation process,and realized the collection of multi-information and feedback of environmental status.The main research content of this paper is as follows:（1）A C-Ink/P（VDF-Tr FE）/Au flexible piezoresistive-piezoelectric dual-mode sensor was designed using conductive carbon ink（C-Ink）as the piezoresistive sensitive material,poly（vinylidene fluoride-trifluoroethylene）（P（VDF-Tr FE））as the piezoelectric sensitive material,and gold（Au）as the conductive electrode.During the bending deformation process,the piezoresistive layer exhibits good detection sensitivity（positive bending S=0.083%/°;negative bending S=-0.004%/°）,achieving precise perception of static information such as deformation size and direction;The piezoelectric layer can accurately detect the magnitude of deformation rate,and its sensitivity to bending deformation is S=41.266 m V/(°s^-1).By collaborating with piezoresistive sensing and piezoelectric sensing,dual-mode sensors achieve multi-information perception（including deformation size,direction,and rate）during the bending deformation process,and can effectively decode complex motion processes.（2）The flexible piezoresistive-piezoelectric dual-mode sensor was embedded into the gelatin gel,and the gelatin based actuaing/sensing dual-mode composite material with asymmetric structure was prepared.The composite material exhibits excellent driving performance in ion solutions of different concentrations and types of anions.In a 3M（NH₄）₂SO₄ solution,the deformation rate of the composite material in the first 5 seconds is 9.090°/s,and the bending angle within 1 minute is 233.678°.In addition,the composite material achieved measurement of bending deformation size and deformation rate under ion stimulation through an embedded dual mode sensor.Finally,the flexible smart gripper constructed based on this composite material can recognize the size of the object and perceive the intensity of feedback environmental stimuli when grasping it.This innovative method of actuation and multi-information perception integration is of great significance to expand the application of smart hydrogels in flexible smart robots,human-computer interaction,biomedicine and other fields.