Natural organisms can convert environmental stimuli into sensory feedback to regulate their body and realize active adaptivity. However, realizing such a feedback-regulation mechanism in synthetic material systems remains a grand challenge. It is believed that achieving complex feedback mechanisms in responsive materials will pave the way toward autonomous, intelligent structure and actuation without complex electronics. Inspired by living systems, we report a general principle to design and construct such feedback loops in light-responsive materials. Specifically, we design a baffle-actuator mechanism to incorporate programmed feedback into the opto-mechanical responsiveness. By simply addressing the baffle position with respect to the incident light beam, positive and negative feedback are programmed. We demonstrate the transformation of a light-bending strip into a switcher, where the intensity of light determines the energy barrier under positive feedback, realizing multi-stable shape-morphing. By leveraging the negative feedback and associated homeostasis, we demonstrate two soft robots, i.e., a locomotor and a swimmer. Furthermore, we unveil the ubiquity of feedback in light-responsive materials, which provides new insight into self-regulated robotic matters.

翻译：自然生物能将环境刺激转化为感官反馈，以调节其身体并实现主动适应性。然而，在合成材料系统中实现这种反馈调控机制仍是一个重大挑战。人们认为，在响应材料中实现复杂的反馈机制将为无需复杂电子设备的自主智能结构与驱动开辟道路。受生命系统启发，我们报告了一种在光响应材料中设计与构建此类反馈回路的通用原理。具体而言，我们设计了一种挡板-执行器机制，将编程反馈融入光机械响应中。仅通过调整挡板相对于入射光束的位置，即可编程实现正反馈与负反馈。我们演示了将一条光弯曲带转变为切换器，其中光强度在正反馈下决定能量势垒，从而实现多稳态形状变形。通过利用负反馈及其相关的稳态维持，我们展示了两种软体机器人，即一个运动机器人与一个游泳机器人。此外，我们揭示了反馈在光响应材料中的普遍性，这为自调控机器人物质提供了新的见解。