Bioinspired Soft Robotics Laboratory, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy.
Laboratory for Bioinspired, Bionic, Nano, Meta Materials and Mechanics, Department of Civil, Environmental and Mechanical Engineering, University di Trento, Via Mesiano 77, Trento, 38123, Italy.
Adv Sci (Weinh). 2023 Mar;10(9):e2205146. doi: 10.1002/advs.202205146. Epub 2023 Feb 1.
Geraniaceae seeds represent a role model in soft robotics thanks to their ability to move autonomously across and into the soil driven by humidity changes. The secret behind their mobility and adaptivity is embodied in the hierarchical structures and anatomical features of the biological hygroscopic tissues, geometrically designed to be selectively responsive to environmental humidity. Following a bioinspired approach, the internal structure and biomechanics of Pelargonium appendiculatum (L.f.) Willd seeds are investigated to develop a model for the design of a soft robot. The authors exploit the re-shaping ability of 4D printed materials to fabricate a seed-like soft robot, according to the natural specifications and model, and using biodegradable and hygroscopic polymers. The robot mimics the movement and performances of the natural seed, reaching a torque value of ≈30 µN m, an extensional force of ≈2.5 mN and it is capable to lift ≈100 times its own weight. Driven by environmental humidity changes, the artificial seed is able to explore a sample soil, adapting its morphology to interact with soil roughness and cracks.
天竺葵科种子是软机器人领域的典范，它们能够在湿度变化的驱动下自主地在土壤表面和内部移动。其移动性和适应性的秘密在于生物吸湿组织的层次结构和解剖学特征，这些结构和特征被几何设计成对环境湿度具有选择性响应。受生物启发，研究了天竺葵（Pelargonium appendiculatum（L.f.）Willd）种子的内部结构和生物力学特性，以设计软机器人。作者利用 4D 打印材料的可重塑能力，根据自然规格和模型，使用可生物降解和吸湿的聚合物，制造出类似种子的软机器人。该机器人模拟了天然种子的运动和性能，达到了约 30µN m 的扭矩值、约 2.5 mN 的拉伸力，并且能够举起自身重量的约 100 倍。在环境湿度变化的驱动下，人工种子能够探索样本土壤，调整自身形态以适应土壤的粗糙度和裂缝。
