Soft robots mimic the agility of living organisms without rigid joints and muscles. Continuum bending (CB) is one type of motion living organisms can display. CB can be achieved using pneumatic, electroactive, or thermal actuators prepared by casting an active layer on a passive layer. The corresponding input actuates only the active layer in the assembly resulting in the bending of the structure. These two different layers must be laminated well during manufacturing. However, the formed bilayer can still delaminate later, and the detachment hampers the actuator's reversible, long-time use. An approach to creating a single material bending actuator was previously reported, for which spatial gradient swelling was used. This authentic approach allows a single material to be manufactured as a bending actuator, allowing easy access to such actuators without lamination. In this study, we show spatial porosity differences in the sponges of polydimethylsiloxane (PDMS) (a common material in soft robotics) can be used to create the required anisotropy for bending. The spongy polymers are manufactured through table sugar templates and actuated by (organic) solvent absorption/desorption. This enables some versatility in the mechanical properties, shape, actuation force, and actuation speed. The one-material system's straightforward production and seamless nature are advantageous for reversible and repetitive bending. This simple method can further be developed in hydrogels and polymers for soft robotics and functional materials.

中文翻译：

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单一材料溶剂驱动聚二甲基硅氧烷海绵弯曲致动器。


软体机器人模仿生物体的敏捷性，没有刚性关节和肌肉。连续弯曲 （CB） 是生物体可以显示的一种运动类型。CB 可以使用气动、电活性或热致动器来实现，这些致动器是通过在被动层上铸造有源层来制备的。相应的输入仅驱动组件中的活动层，从而导致结构弯曲。在制造过程中，这两个不同的层必须很好地层压。然而，形成的双层稍后仍会分层，并且分离会阻碍促动器的可逆长期使用。之前报道了一种创建单一材料弯曲致动器的方法，其中使用了空间梯度膨胀。这种真实的方法允许将单一材料制造为弯曲致动器，从而无需层压即可轻松访问此类致动器。在这项研究中，我们展示了聚二甲基硅氧烷 （PDMS）（软机器人中的一种常见材料）海绵的空间孔隙率差异可用于产生弯曲所需的各向异性。海绵状聚合物通过食糖模板制造，并通过（有机）溶剂吸收/解吸驱动。这使得机械性能、形状、驱动力和驱动速度具有一定的多功能性。单一材料系统的简单生产和无缝特性有利于可逆和重复弯曲。这种简单的方法可以在水凝胶和聚合物中进一步开发，用于软机器人和功能材料。