Research On The Design And Actuation Mechanism Of Bionic Hydrogel Soft Robot

Soft robots were made of flexible materials that can withstand large strains.They have unlimited degrees of freedom and continuous deformation capabilities.They can change their shape and size arbitrarily within a large range.Compared with traditional robots,they have better environmental adaptability.However,the application of new flexible materials made the driving design of soft robots difficult,and it was impossible to follow the design route of traditional robots.At present,soft robots with various driving methods have broad application prospects in the fields of medical detection,deep-sea exploration,covert reconnaissance,and post-disaster search and rescue.Issues,such as weak load bearing capacity,slow response speed,difficult to achieve "tailless" remote control,restrict the practical application of soft robots.In view of the problems of soft robots in remote control and other aspects,this paper combined the advantages of diversity in response to hydrogel-driven excitation methods,used the composite modification mechanism of nano-composite temperature-sensitive hydrogels,explored the actuation mechanism of the hydrogel soft robot under the combined action of material properties and induction heating conditions,designed and produce magnetic temperature-sensitive,constructed the swelling model and the magnetic-thermal coupling finite element model of the magnetic and temperature responsive hydrogel.The specific research work was as follows(1)According to the magnetic induction organic/inorganic cross-linked thermosensitive hydrogel swelling equilibrium state volume phase transition test results at different temperatures,combined with the chemical formula change model of the non-ionic gel and Flory-Huggins mixed free energy theory correction model,the temperature sensitive hydrogel was constructed Mathematical model of glue swelling behaviorUsed Methylene-Bis-Acrylamide(BIS)as the organic crosslinking agent,LAPONITE as the inorganic crosslinking agent,N-isopropylacrylamide(NIPAM)as the temperature sensitive monomer,and nano Fe3O4 as magnetic particles,we made organic cross-linked temperature-sensitive hydrogel(OCTH),magnetic induction organic cross-linked temperature-sensitive hydrogel(MOCTH),inorganic cross-linked temperature-sensitive hydrogel(ICTH)and magnetic induction inorganic cross-linked temperature-sensitive hydrogel(MICTH).The sample was immersed to the swelling equilibrium state,explored its volume and mass changes under different temperature conditionsThe experimental results showed that the minimum critical dissolution temperature(LSTC)of each NIPAM temperature-sensitive hydrogel mentioned in this article was around 30?,and the volume shrinkage rate of the two groups of NIPAM temperature-sensitive hydrogels using inorganic cross-linking agent before and after the volume phase transition(45.60%and 41.63%)were significantly larger than the two groups using organic crosslinking agents(24.22%and 17.10%)According to the chemical formula change model of nonionic gel and Flory-Huggins mixed free energy theory modified model,the swelling behavior mathematical models of organic cross-linked temperature-sensitive hydrogel and inorganic cross-linked temperature-sensitive hydrogel were constructed.Compared with the calculated equilibrium swelling rate(ESR)of each temperature-sensitive hydrogel at different temperatures according to the experimental data,the fitting degree was higher(2)Built a magnetic-thermal coupling simulation model of magnetic and temperature responsive hydrogel with COMSOL,the multiphysics coupling simulation tool.Simulated the magnetocaloric effect and heat transfer phenomenon of magnetic and temperature responsive hydrogel in an alternating magnetic field environment.Studied the influence of magnetic field conditions and magnetic nanometers Fe3O4 particle distribution on induction heating time and the temperature field inside magnetic induction thermosensitive hydrogelThe COMSOL soft was used to establish a finite element simulation model of the magnetocaloric effect of the magnetic and temperature responsive hydrogel.The copper coil was used as a heat source and an alternating current of 10 A was passed to generate the required magnetic field environment to heat the magnetic and temperature responsive hydrogelThe simulation results showed that the UHF magnetic field does have a significant induction heating effect on the magnetic and temperature responsive hydrogel.In the 200-600 kHz magnetic field,the induction heating speed decreases with the increase of the magnetic field frequency,and the smaller the reduction rate of the time required.The heating rate was faster when the density of the nano Fe3O4 particles was higher than when the distribution density was lower(3)Observed the peristaltic crawling gait of fruit fly larvae,the distribution and structure of the feet.Based on the differences of different materials in volume phase transition behavior,water retention,designed the actuators of the parasitic fruit fly larvae hydrogel soft robot,and tested the movement performance of the parasitic fruit fly larvae hydrogel soft robotCombined with the study of the actuation mechanism of hydrogel software robot under the combined action of material properties and induction heating,the magnetic induction temperature-sensitive hydrogel actuator with a differentiated double-layer structure was designed,which can be heated in an alternating magnetic field to achieve bending actuation.The imitated fruit fly larvae hydrogel soft robot was fabricated,and its creeping crawling performance was tested on a rough surfaceThe test results showed that the M-M type double-layer structure flies larvae hydrogel soft robot can complete simple creeping crawling under the ultra-high frequency alternating magnetic field environment with the help of the directional friction provided by the rough contact surface.The creeping speed was 0.23 mm/s(ie 0.009 BL/s),realized the wireless control of the soft robotIn summary,the double-layer structure imitated fly larvae hydrogel soft robot showed good maneuverability by using the difference between MOCTH and MICTH in volume phase transition behavior.It provided reliable theoretical data and experimental basis for the wireless control of soft robots.