Bottom-up strategies have been proposed to create active superstructures capable of executing rudimentary tasks. For instance, swarm robotics utilizes many simple robots with minimal functionalities (such as self-locomotion or basic configurational changes), which, through mutual yet elementary interactions, lead to a global organization with capabilities surpassing those of individual particles. However, these superstructures often suffer from poor cohesive properties and offer limited emergent behavior.
Recently, our group has accumulated evidence suggesting that a viable laboratory model for an active chain consists of self-propelled bots attached together with elastic linkers whose stiffness can be adjusted. When made sensitive to external stimuli such as light, they provide a simple yet versatile platform for investigating emergent behavior in entangled soft robotics.
We have initial evidence demonstrating that these bots, once rendered sensitive to light, can function as controllable active units within the polymer chain. Preliminary experiments indicate that shading part of the chain can induce conformational changes, causing it to spiral. This increases the complexity of the active chain, moving towards the realization of a practical soft robot. For example, by patterning an area deprived of light on a surface (see figure), an aggregate of multiple active chains can rotate and unexpectedly follow the contour of the shaded pattern. This highly nontrivial emergent behavior resulting from the interaction between light and the 2D entangled soft robots underscores the richness of outcomes achievable with this experimental system. Such challenges will be crucial for the future design of soft entangled materials with controllable functions. This project involves image visualization, Python-based data processing, and simulations; do not hesitate to reach us if interested!