| Highly flexible,low Young’s modulus and biocompatible mechanoelastic smart devices,such as remote light-controlled detectors and remotely controllable smart grippers,are able to bypass complex obstacles and walk meandering routes through controllable and reversible smart deformation,working in areas where people cannot physically venture.So highly deformable and fast-responding smart actuators are of increasing interest to researchers.Flexible intelligent actuators can be used in fields such as medical ultra-minimally invasive surgery and military intelligent detection,which is a new generation of flexible intelligent actuators direction of research hotspots.However,most of the current smart actuators are tedious to prepare,and the single driving method and limited driving effect limit their application scope.To this end,a bilayer photothermally responsive flexible actuator,consisting of a photothermally responsive composite hydrogel layer and a polydimethylsiloxane(PDMS)layer,which can be rapidly prepared and driven by a variety of stimuli,has been designed.The photothermal responsive composite hydrogel is prepared by combining the photothermal responsive material graphene oxide(GO),the organic additive hydroxyethyl methacrylate(HEMA)and the temperature sensitive smart hydrogel of poly-N-isopropylacrylamide(PNIPAM).The actuator designed in this study is capable of controllable actuation in a wide range of stimulus conditions including thermal solution,simulated sunlight and lasers.It enables rapid actuation with large bending deformations and is highly stretchable,thus extending the applications for soft body actuators.Details of the research are as follows.(1)PNIPAM/GO/HEMA composite hydrogels with photothermal response properties were prepared,and various composite hydrogels based on PNIPAM smart temperature-sensitive hydrogels were characterized by thermogravimetric analysis,swelling properties,mechanical properties,UV-VIS-IR transmission rate,and photothermal response.And the effects of various materials used in this paper on the composite hydrogels were verified.(2)A photothermally responsive soft actuator with a bilayer structure was constructed using PDMS and the photothermally responsive composite hydrogel PNIPAM/GO/HEMA(PGH),and its driving behavior was studied under stimulation conditions such as thermal solution,simulated sunlight and laser.The results showed that the actuator exhibits good bending behavior,and the optimum GO concentration and the thickness of hydrogel layer were also investigated.In addition,under laser irradiation conditions,the bending direction of the PGH bilayer photothermal response actuator could be controlled to face or move away from the light source by adjusting the illuminated surface of the actuator.Through the study of single and triple layer structures,it was proved that the bilayer structure of the photothermal actuator offered significant actuation advantages.We also used materials with different coefficients of thermal expansion(CTE)to prepare and compare the driving environments and driving effects of other bilayer actuators,demonstrating the advantages of the PDMS/PGH bilayer structure in terms of material selection.(3)Various driving control tests were carried out on PGH/PDMS bilayer photothermal response actuators,and the local control driving of a "Y" actuator and the capture behavior of target balls were designed and realized.In addition,a cross-shaped driver with a symmetrical structure was designed,and the transportation behavior of the target ball was realized by using the thermal response deformation and the change of center of gravity of the actuator.The experimental results showed that the PGH/PDMS bilayer photothermal response actuator in this study could realize independent driving control behavior,which had the potential for intelligent driving application and could promote the design and manufacture of new intelligent systems with driving behavior. |
PDF Full Text Request