A MXene-Based Light-Driven Actuator and Motor with Self-Sustained Oscillation for Versatile Applications

Phototropism and self-oscillation are both self-regulating intelligent movements of biological organisms. However, realizing these intelligent movements in one same artificial actuation system remains a great challenge. Here, by introducing dynamic light-mechanical interaction, a MXene-based actuator is designed and fabricated that can generate unique self-adaptive light-driven actuation from the equilibrium state of phototropic deformation to self-oscillation. The actuator can autonomously track the incident light, showing a sunflower-like phototropism. Moreover, by simply installing a load on the actuator to induce self-shadowing-enabled negative feedback loop, it can carry the load to continuously oscillate under constant light irradiation, with a frequency of 6.5 Hz, an amplitude of 2.6 mm, and a load-to-weight ratio value of 4.7. The oscillation frequency and amplitude can be further adjusted by the incident light power, actuator length, and weight of the installed load. This oscillator can serve as an intelligent light-powered motor platform. By installing diverse accessories with different functions on the oscillator, it can realize various applications, including information transmission, light-induced power generation, bionic motions, and multi-mode intelligent switches. These results provide a simple and versatile strategy for designing a self-adaptive oscillator driven by light and show the prospect of the oscillator in light-powered engines and smart machinery systems.