The Fabrication Of An Electric/Magnetic Stimulus-Responsive Hydrogel And The Application In Soft Robotics

As one of the most promising smart materials,stimulus-responsive hydrogels can flexibly change their volume or shape in response to external stimuli.They have shown great promise for applications in various components of soft robots.Currently,although considerable progress has been made in the study of single-stimulus-responsive hydrogels,exploring multistimulus response of hydrogels remains a major challenge.Here,we prepared a dual-stimulusresponsive hydrogel capable of producing electrical response in a wide range of pH environments with fast magnetic response,low voltage actuation and good reversibility and reproducibility by compounding an electric field stimulus-responsive hydrogel with magnetic functional particles.Firstly,hydrogels with different dosages of cross-linking agents,different polyvinyl alcohol(PVA)concentrations and different ratios of chitosan(CS)and carboxymethyl chitosan(CMCS)were designed and manufactured by parallel experimental groups.And we compared the properties of the fabricated hydrogel materials by electric response test,water retention test,SEM,tensile test and reversibility test,and selected the optimal ratio as the dosage group of electric field stimulation response matrix gel(ERH).An electro-responsive basic gel system with wide range of acid-base adaptability,fast deflection at low voltage and good reversibility and reproducibility was produced.Secondly,based on the first part of the study,we compounded the magnetic functional particles with the ERH system and avoided the depletion of the amino and carboxyl groups in the gel system due to the chelating effect on the magnetic particles by grafting the magnetic nanoparticle surface.The final product is an electrical/magnetic dual stimulation response hydrogel(EMRH)capable of producing an electrical response in a wide range of pH environments with a fast magnetic response,low voltage actuation,and good reversibility and reproducibility.Finally,based on the first and second part of the study,the application of EMRH in the field of soft robotics was studied and explored.Firstly,EMRH was prepared into different hydrogel actuators,and the remote control of the electro-sensitive hydrogel was realized by introducing the cloud control into the EMRH control system through intelligent control devices.On this basis,the asynchronous electric response control and the precise magnetic response control of EMRH are realized through the design of spatial electric field and spatial magnetic field,i.e.,the hydrogel can be remotely networked and fine-grained control system design is realized.Subsequently,by studying the change of resistance of EMRH with strain.the possibility of its use as a soft robot sensing was verified,and the preliminary exploration for the application of EMRH in the sensing field was made.In this study,a hydrogel material with multi-stimulus responsiveness,broad environmental adaptability and multifunctionality was developed.By designing and fabricating matching spatial electric field and spatial magnetic field control devices,the hydrogel can be remotely networked and finely controlled,and the possibility of EMRH as soft robot sensing is further verified,which provides a new idea for exploring complex soft robot intelligent materials and corresponding control systems.