Research Projects

In the recent years, active matter is an emerging area of research because of its enormous applications in the fabrication of different types of nanorobots, artificial swimmers and other self-driven systems. Active matter is a special class of soft matter systems, which is inherently driven away from equilibrium. The constituents of such systems are capable of self propelling by their own in the environment and hence known as active or self-propelled particles. It is expected that such particles exhibit interesting features in transport behaviour which are different from that of passive Brownian particles. The collection of bacteria, motile micro-sized organisms, Janus particles, flock of birds, microrobots, and hexbugs are some good examples of active matter. One of the main aspects of active matter is that these systems are always out of equilibrium since they self propel by their own. Therefore, it is quite challenging to model and study these systems using the conventional equilibrium statistical mechanics. There exists some standard models like active Brownian particle (ABP) model, Run and Tumble model and the active Ornstein-Uhlenbeck particle (AOUP) model for investigating the dynamical behaviour of such particles. These models are successful in resulting many interesting phenomena of such systems. But, active Brownian motion assumes an instantaneous friction, which is a well justified assumption for a Newtonian fluid. With no memory effect of the medium. However, in many situations, these particles are exposed to non-Newtinonian environments with a finite memory, which are often found to be viscoelastic in nature. In the recent years, the inclusion of inertia in ABP models with viscous medium results inertial delay, accumulation near boundary, motility induced phase transition, motility induced temperature difference between the coexisting phases and so on. However, the inertial active dynamics in viscoelastic suspension has received only limited attention to the steady state transport properties. Hence, the main objective of this proposal is to consider inertial active dynamics (especially AOUP model) in viscoelastic suspension and check how the inertial influence modulate the transport behaviour of such systems in various circumstances. In our recent study, we observed that inertial charged active dynamics in a viscoelastic suspension results a memory induced reentrant type behaviour (active to passive and then to active) in the presence of a finite magnetic field. Similarly, the inertial dynamics of a particle in a non-Newtonian environment results a memory induced transition from random self propulsion to local circular motion. This work is under way and will communicate it soon. Further, we plan to investigate the inertial dynamics in viscoelastic environment in in both single particle and collective level and in various circumstances of the dynamics.