Active Matter Research Group

Research in active soft matter seeks a deep understanding of mechanisms underlying processes and cooperative behavior observed in nature and biological systems using mathematical/physical laws to develop models and novel materials. Examples of active matter include humans, bacteria, birds, fish, and other organisms, besides more broadly noise driven motors and pumps such as dynein and myosin, and robots.

One focus of research involves finding effective strategies for self-assembly of structures from simple elements exploiting electric, magnetic, shape, chirality, memory, and capillary interactions, which encode a function for which DNA is a prime example. Further, self-organizing self-propelled particles would prove useful in the fabrication of nano-structures and micro-mechanical devices where direct manipulation is impossible.  Therefore the scope of active soft matter goes beyond active matter where the object derives function by consumption of energy as in living systems, but also self-assembly due to entropic consideration in thermal systems as in disorder-order transition in liquid crystals. Development in out-of-equilibrium physics and self-assembly techniques has lead to the appreciation that even simple local physical interactions can give rise to complex multi-layered structures and cooperative behavior. Besides the development of new materials, such an approach has potential for the study of behavior and cooperative phenomena as well. Energy saved by aerodynamic drafting has been given as a reason to explain flock patterns in birds, and leader-less nearest neighbor statistical models have been used to explain large scale prey evasion strategies by fish schools and animal herds.

Another focus involves understanding biological observations to design new materials and systems. Nature has encountered and solved many complex problems through natural selection. These multifaceted working solutions are not optimized because of the history of their development and their use in multiple tasks. Therefore there is significant scope for development after the basic principle is identified. A well recognized example is fixed wing airplanes which can be traced to humans epic dream for flight that led first to wings based on mimicry of birds (bio-mimetics), and discovery of the Bernoulli’s principle. Refinement using experimentation with wind tunnels and computational fluid dynamics followed which co-developed over the last century. In spite of this commercial success, the original observation of flapping flight remains poorly understood, and is still an active field of fundamental research with implication for insect sized flying drones with high maneuverability.   Other examples at various stages of this trajectory include the recognition that spider silk has higher tensile strength than steel while being significantly lighter, development of new adhesives which stick in wet environments – something routinely accomplished by marine life and bio-films, and design of inhaled drug delivery based on wind dispersed seeds.

The group is supported by the Clark University Dean of Research Office.