Asymmetric fluttering ferromagnetic bar-driven inertial micropump in microfluidics

Even though microfluidics has been successfully used in minimizing complicated and onerous processes, the pumping and tubing systems used with it are yet undeveloped and need immediate development. The present study developed a fluttering bar-driven micropump, mounted on a polydimethylsiloxane microfluidic system. The pump consists of a rectangular ferromagnetic bar and a fan-shaped chamber with an inlet and outlet. Through various experiments, the net flow was examined as a function of chamber shape, inlet and outlet channel location, rotating center of the magnet, and rotational speed. Using high-speed camera and image analysis, the net flow was found to be generated by the fluid inertia associated with the varying reciprocating speeds of the bar inside the fan-shaped chamber. Depending on the locations of the inlet and outlet, the cycle time taken to circulate the loop was significantly reduced from 200 to 4 s. The flow rate of the micropump ranges from 48–225  μ l/min, which is proportional to the rotational speed of the magnet (150–3000 rpm). Using a fluttering bar-driven inertial micropump, the microfluidic system not only provides improved mixing, but also eliminates certain problems associated with external tubing and connection.