Abstract
This paper presents the high-speed microrobot driven by permanent magnet in a microfluidic chip. The comprehensive analysis of fluid force, the optimum design and its fabrication was conducted to reduce the fluid force on the magnetically driven microrobot by developing fine V groove pattern on the microrobot. Riblet surface, which is regularly arrayed V grooves, were employed to reduce fluid friction on the microrobot. The upward force is generated by the wedge effect and it generates lubricant film thickness between the microrobot and the glass substrates. Optimization process was conducted to design riblet surface on the microrobot in order to maximize lubricant film thickness. The Ni and Si composite fabrication was employed to form the optimum riblet shape by anisotropic Silicon (Si) wet etching and deep reactive ion etching. The evaluation experiments show the microrobot can be actuated up to 90 Hz, which is about 10 times higher than the original microrobot.
