An Autonomous Soft Actuator with Light‐Driven Self‐Sustained Wavelike Oscillation for Phototactic Self‐Locomotion and Power Generation

Abstract

Mimicking the intelligence of biological organisms in artificial systems to design smart actuators that act autonomously in response to constant environmental stimuli is crucial to the construction of intelligent biomimetic robots and devices, but remains a great challenge. Here, a light-driven autonomous carbon-nanotube-based bimorph actuator is developed through an elaborate structural design. This curled droplet-shaped actuator can be simply driven by constant white light irradiation, self-propelled by a lightmechanical negative feedback loop created by light-driven actuation, time delay in the photothermal response along the actuator, and good elasticity from the curled structure, performing a continuously self-oscillating motion in a wavelike fashion, which mimics the human sit-up motion. Moreover, this autonomous self-oscillating motion can be further tuned by controlling the intensity and direction of the incident light. The autonomous actuator with continuous wavelike oscillating motion shows immense potential in light-driven biomimetic soft robots and optical-energy-harvesting devices. Furthermore, a self-locomotive artificial snake with phototaxis is constructed, which autonomously and continuously crawls toward the light source in a wave-propagating manner under constant light irradiation. This snake can be placed on a substrate made of triboelectric materials to realize continuous electric output when exposed to constant light illumination.

Robust Dynamics of Synthetic Molecular Systems as a Consequence of Broken Symmetry

“…Applying stimuli-responsive materials, oscillatory motions, and directional motions has also been reported [29][30][31][32][33][34][35][36][37][38][39][40][41]. Stimuli-responsive materials generally terminate their motion when the systems reach equilibrium.…”

Recent Advances in Photoactuators and Their Applications in Intelligent Bionic Movements

“…Hu's group fabricated a PDMS/CNT oscillator by spincoating technique under constant white light irradiation with an oscillation displacement of 13.9 mm and frequency of 0.3 Hz. [69] In Figure 1E, "F actuation " is generated by the expansion of PDMS during the illumination process. Due to high pre-stress and stored elastic potential energy, the PDMS/CNT bi-layered film is in a curled state and exhibits excellent elastic properties, that is, it generates an elastic force "F elastic ".…”

“…Reproduced with permission. [69] Copyright 2020, Wiley-VCH. the isotropic phase transition temperature (T trans ) under light irradiation, resulting in a decrease in the volume.…”

“…www.advopticalmat.de motion of the CNT/PDMS actuator. [69] At present, photoactuators are still facing great challenges in achieving flight-like motion. In future, it is necessary to design high vibration frequency, large driving force, and light weight actuators by structural and shape reconfiguration to achieve flying.…”

Robust Dynamics of Synthetic Molecular Systems as A Consequence of Broken Symmetry

“…[23] (a) (b) (c) Applying stimuli-responsive materials, oscillatory motions and directional motions have also been reported. [27][28][29][30][31][32][33][34][35][36][37][38][39] Stimuli-responsive materials generally terminate their motion when the systems achieve equilibrium. The oscillations in those studies were motivated by the coupling of the directionality of external energy-supply and the time-delayed transition of materials.…”