Multiple Hydrogen Bonded 3D‐Printed Elastomers with Enhanced Toughening by Photothermal Dual Curing for Customizable Biomimetic Flexible Grippers

Abstract

This study develops low‐viscosity, two‐component polycaprolactone (PCL)‐based 3D‐printed elastomers via photothermal dual curing. To prevent a sudden increase in viscosity from the direct introduction of hydrogen bonding in the oligomer, multiple hydrogen bonding components are innovatively added into the resin system in the form of the chain extender 12NH. The samples undergo thermal treatment after light curing. Incorporating 12NH, which retains unreacted isocyanate functionality, into the elastomer's macromolecular long‐chain forms an interpenetrating network of multiple hydrogen bonds, dynamic covalent bonds, and a micro‐phase separation. The resultant elastomers exhibit superior mechanical properties, achieving a tensile strength of 43.5 MPa and tensile toughness of 213.1 MJ m−3, while maintaining high biocompatibility. These properties surpass those of existing PCL‐based reduced photopolymerized 3D‐printed elastomers. Subsequently, complex lattice structures and bionic flexible grippers are successfully printed, validating their potential in applications requiring efficient gripping and rapid response. This study offers novel concepts for designing 3D‐printed elastomers that optimize the balance between high strength and toughness, precision molding, and biosafety, facilitating the development of tailored manufacturing for flexible robotics and implantable medical devices.