Optimal humidity-responsive actuators of heterostructured MXene nanosheets/3D-MXene membrane

Intelligent actuators offer a lot of potential for use in soft robots, artificial muscles, sensors since it can alter shape in response to external stimuli. However, the stiffness of the material and the constrained specific surface area brought on by the dense stacking of materials restrict the response of the conventional humidity-responsive actuators. Herein, optimal humidity-responsive actuators of MXene were developed by designing topologies of heterostructured membrane of stacked nanosheets and 3D wrinkled MXene (3D-MXene). In this configuration, the stacked MXene nanosheets sustain the device's overall strength, while the 3D-MXene layer significantly improves the device's moisture absorption and decreases its stiffness. Importantly, the actuators have been strengthened due to the van der Waals forces at the interface of the stacked nanosheets and 3D-MXene. The fabricated MXene/3D-MXene actuator has exhibited remarkable response speed and deformation ability, obviously superior to any previously reported humidity-responsive actuators. By combining excellent electrical conductivity, the developed actuators demonstrated rapid response for electrical switches. This work highlights the significant potential for developing high performance responsive actuators by designing heterostructured configurations for applications in intelligent switches, soft robotics and synthetic muscles.