Bioinspired Phototropic MXene-Reinforced Soft Tubular Actuators for Omnidirectional Light-Tracking and Adaptive Photovoltaics

Endowing artificial advanced materials and systems with biomimetic self-regulatory intelligence is of paramount significance for the development of somatosensory soft robotics and adaptive optoelectronics. Herein, a bioinspired phototropic MXene-reinforced soft tubular actuator is reported that exhibits omnidirectional self-orienting ability and is capable of quickly sensing, continuously tracking, and adaptively interacting with incident light in all zenithal and azimuthal angles of 3D space. The novelty of the soft tubular actuator lies in three aspects: 1) the new polymerizable MXene nanomonomer shows high compatibility with liquid crystal elastomer (LCE) matrices and can be in situ photopolymerized into the polymer networks, thus enhancing the mechanical and photoactuation properties; 2) the distinct hollow and radially symmetrical structure facilitates the actuator with fast photoresponsiveness and phototropic performance through retarding the heat conduction along the radial direction; 3) the MXene-LCE soft tubular actuator simultaneously integrates sensing, actuation, and built-in feedback loop, thus leading to a high light-tracking accuracy and adaptive phototropism like a hollow stem of plants in nature. As a proof-of-concept demonstration, an adaptive photovoltaic system with solar energy harvesting maximization is illustrated. This work can provide insights into the development of artificial intelligent materials toward adaptive optoelectronics, intelligent soft robotics, and beyond.

Automated summary

This article reports on a bioinspired phototropic MXene-reinforced soft tubular actuator that has omnidirectional self-orienting ability and can interact with incident light in all zenithal and azimuthal angles. The innovation of this actuator lies in its optimized materials and structure, which enable fast photoresponse and high light-tracking accuracy. A proof-of-concept demonstration of its application potential in solar energy harvesting is provided.