Design and Control of Micro Robotic Systems
Micro-robotics is an emerging field of research where the focus areas are physical actuation, system control, materials, sensor research and so on. It is an interdisciplinary field where researchers from communities such as physics, chemistry, engineering (biotech, mechanical, comp science) have a role to play. The goal is to contribute to the development of a small-scale robotic system that can see application in the fields of targeted medicine, environment monitoring, water body treatment, small scale manufacturing, and so on. A micro-robot is a controllable machine of micron scale with application specific capabilities in addition to generic functions such as motion, sensing and control mechanism. Scaling robotic systems to micro-scale forces us to focus on physical parameters such as surface tension, adhesion and drag instead of mass and inertia. The actuation machines must now be similar to cilia, pseudopodia, flagella as observed in the nature. There has been research in development of actuation mechanisms at micron scale such as magnetically actuated rigid helices, cilia and sperm-mimetic synthetic tails, chemically powered spherical particles and cannons, synthetically engineered bacteria, muscle cells, etc. Parallel research in this field studies the swarm behaviour and control of such microrobots. There are experimental studies of behaviour of different shaped para-magnetic particles under the influence of rotating 3D magnetic field in literature.[3, 4] There is also a study on active matter that is independent of the influence of external control. In our work, we are studying the effect of external control on active particle behaviour. In this direction, we have done a few simulations to model the efficiency of a swarm in reaching a defined target region. We have studied the swarm behaviour with and without controlling the mean location of the swarm with the help of external control like magnetic field. We designed a hardware setup to study the effect of external control on active particles. The setup uses a speaker to emulate Brownian motion of small spherical particles on a flat plate. The effect of magnetic field has been emulated by tilting the plane of the base-plate so as to move the swarm of vibrating particles towards a target region. In our future work, we plan to explore the effect of change in the design of each particle to study its effect on the entire swarm and also explore the changes of control parameters over the same.
References  Clemens Bechinger et al. “Active particles in complex and crowded environments”. In: Rev. Mod. Phys. 88 (4 Nov. 2016), p. 045006. doi: 10.1103/RevModPhys.88.045006. url: https://link.aps.org/doi/10.1103/RevModPhys.88.045006.  Hakan Ceylan et al. “Mobile microrobots for bioengineering applications”. In: Lab Chip 17 (10 2017), pp. 1705–1724. doi: 10.1039/C7LC00064B. url: http://dx.doi.org/ 10.1039/C7LC00064B.  Hui Xie et al. “Reconfigurable magnetic microrobot swarm: Multimode transformation, locomotion, and manipulation”. In: 4.28 (2019). doi: 10.1126/scirobotics.aav8006.  Jiangfan Yu et al. “Ultra-extensible ribbon-like magnetic microswarm”. In: Nature Communications 9.1 (Aug. 2018), p. 3260. issn: 2041-1723. doi: 10.1038/s41467- 018- 05749-6. url: https://doi.org/10.1038/s41467-018-05749-6.