Light-driven transformations in entangled active matter

California blackworms (Lumbriculus variegatus) are freshwater aquatic worms that entangle with one another, forming aggregate structures commonly referred to as worm blobs. Biologically, the entangled state of worms helps them in the efficient execution of vital functions such as temperature maintenance, moisture control, oxygen regulation, and collective locomotion. From the active matter perspective, these tangled worm blobs represent a remarkable material that can autonomously self-assemble, shape-shift, and exhibit other emergent collective functions. Here, we investigate the response of these worm blobs to light exposure. It had been shown previously that blackworms are negatively phototactic in nature, i.e., they tend to move away from light. We leverage this behavior of worms to control their collective motion through a remotely applied stimulus. To this end, we study the dynamic response, shape transformation, and adaptive behavior of entangled living matter as the function of programmed light. Moreover, blackworms show the tendency to entangle with passive material present in their proximity, due to thigmotaxis. The interplay of these blackworms’ intrinsic behaviors can be harnessed to develop strategies aimed at light-guided material transportation and/or assembly through the utilization of entangled active matter.