Bio-Inspired Miniature Soft Robots Fueled By Light

Abstract

Energy sustainability poses a great challenge in miniaturised soft robotics. Light, as renewable and clean energy, is promising to power, actuate and control such robots. However, efficient, high-speed and high-power actuators operating on light-provided power are still in their infancy and subject to intensive research. Here, we demonstrate photo-thermal bimorph actuators based on polydimethylsiloxane (PDMS), graphene (G), and muscovite mica. The PDMS/G/Mica photo-thermal actuator converts light efficiently to displacement and force. Under illumination, the PDMS/G/Mica actuators achieve a large curvature change of 0.76 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> at moderate light intensities of 150 mW/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , beyond that of most photo-thermal actuators reported in the literature so far. The actuators are further integrated into bio-inspired, photo-responsive soft robotic structures such as flower petals and inchworms to demonstrate their suitability for various future applications.