Rapid Photothermal-Responsive Soft Hydrogel Actuator Contained Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene and Laponite Clay with Enhanced Mechanical Properties
Siyuan Diao, Lili Meng, Christian Mark Pelicano, Jiajia Huang, Zhihong Tian, Feili Lai, Tianxi Liu, Shaokui Cao
Abstract
Photothermal responsive hydrogels are widely used in bionic soft actuators due to their remote-controlled capabilities and flexibility. However, their weak mechanical properties and limited responsiveness hinder their potential applications. To overcome this, we developed an innovative laponite/MXene/PNIPAm (L x M y PN) nanocomposite hydrogel that is mechanically robust and exhibits excellent photothermally responsive properties based on abundant hydrogen bonds. Notably, laponite clay is used as a co-cross-linking agent to improve the mechanical properties of L x M y PN hydrogel, while MXene nanosheets are added to promote the photothermal responsiveness. The resulting L 3 M 0.4 PN nanocomposite hydrogel exhibits enhanced mechanical properties, with a compressive strength of 0.201 MPa, a tensile strength of 90 kPa, and a fracture toughness of 27.25 kJ m –2 . In addition, the L 3 M 0.4 PN hydrogel displays a deswelling ratio of 73.6% within 60 s and experiences an excellent volume shrinkage of 82.4% under light irradiation. Furthermore, hydrogel actuators with fast response behaviors are constructed and employed as grippers capable of grasping and releasing target objects. Overall, this high-strength and fast-responsive hydrogel actuator is beneficial to paving the way for remote controlled soft robots.