Investigation On High Precision Vat Photopolymerization 3D Printing Of Hydrogel And Bionic Adhesive Devices

Vat photopolymerization 3D printed hydrogels have been widely used in tissue engineering,drug delivery,flexible electronics,soft robotics and so on.In this thesis,vat photopolymerization 3D printing were systematically introduced based on technology types and materials.Besides,the advances in photopolymerization 3D printing hydrogels in biomedical,smart soft actuator devices and flexible electronics are also summarized detailed.Therefore,the potential applications of photopolymerization 3D printed hydrogels as tissue engineering-like materials for bionic adhesion devices were explored.In response to the current requirements of multi-scale structuring of functional hydrogels(micro-macro),biocompatibility,design of high-strength and high-toughness properties,and technical problems of complex structure molding and manufacturing.This thesis focuses on the preparation of structured hydrogels by high-precision 3D printing technology,with the idea of bionic structure construction,mechanical property optimization and adhesion device construction.(1)A new process for high-precision 3D printing of hydrogels was established through DMSO solvent-assisted,metal ion coordination and water balance strategies to prepare high-fidelity photocurable 3D hydrogels with tunable mechanical properties.Besides,the effects of different ratios of mixed solvents on 3D printing of hydrogels were investigated in detail.The strong hydrogen bonding between DMSO and water improves the evaporation enthalpy of hydrogel ink and solves the problem of collapse and deformation of hydrogel due to water loss in the 3D printing process.In addition,by adjusting the ion coordination time and water balance time,the mechanical properties of the hydrogel can be regulated in a wide range,providing a material basis for the preparation of functional hydrogel devices with customized mechanical properties.Therefore,a simulated human tissue and organ model was prepared by lightcuring 3D printing technology,which has excellent fidelity as well as mechanical strength of tissue-like organs and provides good support for biomedical simulation,teaching,and preoperative training reference.(2)Design and construction of 3D printed hydrogel-based imitation octopus sucker structures and adhesion devices: A series of hydrogel sucker structures were designed,and 3D printed,and the basic physicochemical,mechanical and adhesion properties of the hydrogel sucker were systematically investigated,and it was found that the sucker could effectively improve the adhesion and stability by interfacial water sealing compared with the conventional hydrophobic and dry materials.The experiments and finite element analysis show that the hydrogel suckers with 5 mm radius,30° inclination angle and 1 mm wall thickness have the highest adhesion force in air and underwater,which is 48.46 ± 3.93 k Pa in air environment and 57.19 ± 1.93 k Pa in underwater environment.liquid environment and surface roughness also have good adhesion.Finally,the pneumatic hydrogel gripper with integrated bionic suction cup structure can effectively grip objects underwater and in the air and achieve autonomous release.Given the reversible adhesion of the bionic hydrogel suction cups and grippers with good underwater adaptability,they have a promising future in the field of intelligent adhesion systems and soft robotics.