Journal of Mechanisms and Robotics-Transactions of the ASME, vol.13, no.6, pp.1-9, 2021 (SCI-Expanded)
The importance of an untethered microrobotic platform that can operate on high flowrate
microfluidic channels for in vitro applications is increasing rapidly. This article presents a
method to manipulate a microrobot in a fluidic chip when high flowrates (4 ml/min, 82.304
mm/s) are applied. This method is based on a novel permanent magnet-based diamagnetic
levitation configuration. This configuration includes a thin layer of pyrolytic graphite,
which is placed just below the microrobot. In this way, microrobot stability and manipulation capability are increased. Also, we aim to increase the longitudinal forces imposed on
the microrobot to withstand the drag force proportional to the flowrate. Hence, magnetic
field lines are generated more linearly around the microrobot by a different combination
of permanent magnets. The proposed magnetic configuration, named “KERKAN configuration,” significantly improves the microrobot’s longitudinal forces. In this configuration, two
different ring-shaped ferromagnetic magnets are used. One of the magnets has a smaller
diameter than the other magnet. A combination of one smaller and one bigger magnet is
placed above and below the microrobot. To validate the advantages of this configuration,
analytical and simulation studies are conducted. Their results are then compared with
experimental results. Experimental results are on par with analytical and simulation
studies. KERKAN configuration has a lower displacement than the next best configuration
at the highest flowrate we applied (relatively 3301 μm, %21.8)