Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095 USA.
Department of Mechanical and Aerospace Engineering, University of California Los Angeles, Los Angeles, CA 90095 USA.
Sci Robot. 2023 Apr 19;8(77):eadf4753. doi: 10.1126/scirobotics.adf4753.
As the field of soft robotics advances, full autonomy becomes highly sought after, especially if robot motion can be powered by environmental energy. This would present a self-sustained approach in terms of both energy supply and motion control. Now, autonomous movement can be realized by leveraging out-of-equilibrium oscillatory motion of stimuli-responsive polymers under a constant light source. It would be more advantageous if environmental energy could be scavenged to power robots. However, generating oscillation becomes challenging under the limited power density of available environmental energy sources. Here, we developed fully autonomous soft robots with self-sustainability based on self-excited oscillation. Aided by modeling, we have successfully reduced the required input power density to around one-Sun level through a liquid crystal elastomer (LCE)-based bilayer structure. The autonomous motion of the low-intensity LCE/elastomer bilayer oscillator "LiLBot" under low energy supply was achieved by high photothermal conversion, low modulus, and high material responsiveness simultaneously. The LiLBot features tunable peak-to-peak amplitudes from 4 to 72 degrees and frequencies from 0.3 to 11 hertz. The oscillation approach offers a strategy for designing autonomous, untethered, and sustainable small-scale soft robots, such as a sailboat, walker, roller, and synchronized flapping wings.
随着软机器人领域的发展，完全自主性变得备受追捧，特别是如果机器人的运动可以由环境能源提供动力。这将在能源供应和运动控制方面呈现出一种自给自足的方法。现在，可以通过在恒定光源下利用刺激响应聚合物的非平衡振荡运动来实现自主运动。如果可以利用环境能源为机器人供电，那将更加有利。然而，在可用环境能源的功率密度有限的情况下，产生振荡变得具有挑战性。在这里，我们基于自激振荡开发了具有自我可持续性的全自主软机器人。通过建模的辅助，我们成功地通过基于液晶弹性体 (LCE) 的双层结构将所需的输入功率密度降低到约一太阳水平。低强度 LCE/弹性体双层振荡器“LiLBot”在低能量供应下的自主运动是通过高光热转换、低模量和高材料响应性同时实现的。LiLBot 的峰值-峰值幅度可调，范围从 4 度到 72 度，频率从 0.3 赫兹到 11 赫兹。这种振荡方法为设计自主、无绳和可持续的小型软机器人提供了一种策略，例如帆船、步行机、滚轮和同步拍打翅膀。
