(9i) Autonomous Navigation of Colloidal Robots Via Shapeshifting

Chemotactic bacteria swim autonomously through complex media to regulate their environment and find new energy sources. By contrast, the ability to design and create active colloids capable of autonomous navigation through structured environments remains limited. To achieve autonomous navigation, the colloidal robots should be able to collect and process information around their environment and execute suitable actions. In this talk, we introduce a new strategy of autonomous navigation for active colloids system based on shifting shapes and symmetries. Previous studies have shown that shapes and symmetries of active colloids can be used to direct desired complex motions. In our two-step approach, the local stimulus field determines the shape of a responsive microparticle, which in turn directs its motion powered by an orthogonal energy input. The particle material and shape serve as information-rich media in which to encode the particle velocity as a function of the local stimulus field. Different response functions will enable a variety of functional behaviors, such as stimulus seeking, avoidance, and regulation. We studied the linked autophoretic spheres systems and program the shape of the autophoretic clusters under different stimulus. Our results show that both chemoattractant and chemorepellent behaviors can be achieved with shapeshifting autophoretic clusters, which can be used to design new synthetic colloidal robots.