High-speed magnetic microrobot actuation in a microfluidic chip by a fine V-groove surface

This video shows high-speed microrobotic actuation driven by permanent magnets in a microfluidic chip. The microrobot has a milliNewton-level output force from a permanent magnet, micrometer-level positioning accuracy, and drive speed of over 280 mm/s. The riblet surface, which is a regularly arrayed V-groove, reduces fluid friction and enables high-speed actuation. Ni- and Si-composite fabrication was employed to form the optimum riblet shape on the microrobot’s surface by wet and dry etching. The evaluation experiments show that the microrobot can be actuated at a rate of up to 90 Hz, which is more than ten times higher than that of the microrobot without a riblet.