Metamaterials have attracted wide scientific interest to break fundamental bounds on materials properties. Recently, the field has been extending to coupled physical phenomena where one physics acts as the driving force for another. Stimuli-responsive or 4D metamaterials have been demonstrated for thermo-elasticity, magneto-optics or piezo-electricity. Herein, a soft, ultra-compact and accurate microrobot is described which can achieve controlled motion under thermal stimuli. The system consists of an organized assembly of two functional structures: a rotational and a translational element. Both elements are designed basing upon the principle of the thermoelastic bilayer plate that bends as temperature changes. Samples are fabricated using gray-tone lithography from a single polymer but with two different laser writing powers, making each part different in its thermal and mechanical behaviors. Excellent motion-controllable, reversible and stable features in a dry environment are verified by simulations and experiments, revealing broad application prospects for the designed soft micro actuators.

超材料引起了广泛的科学兴趣，以打破材料特性的基本界限。最近，该领域已扩展到耦合物理现象，其中一种物理作为另一种物理的驱动力。刺激响应或 4D 超材料已被证明用于热弹性、磁光或压电。本文描述了一种柔软、超紧凑且精确的微型机器人，它可以在热刺激下实现受控运动。该系统由两个功能结构的有组织的组件组成：旋转元件和平移元件。这两个元件的设计均基于随温度变化而弯曲的热弹性双层板的原理。样品是使用灰色调光刻从单一聚合物制成的，但具有两种不同的激光写入功率，使每个部件的热性能和机械性能都不同。通过仿真和实验验证了在干燥环境下运动可控、可逆和稳定的优异特性，揭示了所设计的软微执行器的广阔应用前景。