Magnetically Levitated Microrobotic Mixer

Abstract: Microfluidic systems, when combined with microrobots, offer enhanced precision in chemical synthesis by precisely controlling reaction conditions. These systems, when integrated with analytical tools, allow for real-time monitoring and are cost-efficient due to their minimal volume requirements, thereby reducing risks associated with hazardous chemicals. In our study, we have investigated the mixing efficiency of Thymolphthalein indicator with NaOH solution in a magnetically levitated microrobotic mixer. A PMMA microfluidic chip was used to transfer fluid containing two different solutions and achieve fast and efficient mixing. By adjusting five different flow rates and altering the rotational speeds of the microrobots, the mixing efficiency was observed. The studies were carried out under the laminar regime, with incompressible Newtonian flow rates and varying actuator speeds. The measurement of mixing efficiency was accomplished through the calculation of changes in pixel intensity observed in microscopic images acquired throughout the mixing process. The presence of the microrobots resulted in the best efficiency at 80.37% at 500 rpm and 7 mL/min flow rate. Their potential in advanced reactions, such as nanoparticle synthesis and encapsulation, suggests promising avenues for improving product yields.