The structure and chemistry of biological bodies from nature after millions of years of evolution and optimization has inspired the development of a large variety of biomimetic materials. However, the mechanism and underlying assembly rules in a dynamic manner remain largely unexplored. We have designed Janus colloidal particles that can self-propel and interact with others using the energy supplied by externally applied electric field. Moreover, the interaction between particles can be conveniently tuned remotely, so rich dynamic behavior can be observed and investigated in one system.
Another active system we are interested in is based on purified microtubules and kinesin motors, which are responsible for intracellular and cellular transport in cells. We use purified components in vitro to construct active polymer networks and study a series of interesting problems relevant to non-equilibrium hydrodynamics and reversed energy cascade unique to active systems.
The physiological conditions where life is present and functional are usually water based. And it is always noisy. Dynamic pathways with a lot of uncertainties are an essential route prebiotic materials took to become living matter. Inspired by this rule of thumb in the biological world, we aim to make constructive use of biasing random noise in the service of new practical engineering problems, such as designing microscopic limbless swimmers and enabling spontaneous accumulation of matter. Understanding physical laws of motion and assembly rules in physiological conditions is of fundamental importance, as well as practical potential of guiding the design of soft robots and medical devices operating in living cells.
Unlike oversimplified model systems, real life systems are usually crowded with a large variety of coexisting materials. Moreover, these systems are maintained out of equilibrium, which makes it more challenging to study the interactions and ordering processes. We design mixtures of active and passive components with different functionalities to probe the effective interactions between components in complex environments, with the help of well-controlled external field as energy supplier, trigger or force gauge.