Non-contact on-chip manipulation of 3-D microtools and its applications (magnetically modified soft microactuators for particle manipulation)

This chapter describes a novel non-contact manipulation system using an on-chip, magnetically driven micro-tool (MMT) rather than conventional biomanipulation by hand, which has a higher risk of contamination and lower success rate and repeatability. MMTs can sort particles individually, and have the unique feature that they can be installed directly in a microchannel (width = 150 μm), unlike conventional cell sorting systems. The drive unit was significantly improved by focusing magnetic field on-chip and reduced the magnetic interaction region. Also, we have investigated an active size controlled droplet generation system by using magnetically driven microtool (MMT). With a lateral motion of the MMT in microchannels, the continuous phase can be pinched off by the movement of MMT to obtain size-controlled droplets actively.