On-chip magnetically driven micro-robot for enucleation of oocyte

We developed a magnetically driven microtool (MMT) used in a microfluidic chip for enucleation of oocyte. To achieve technological innovation, weight of the tool is about 1/300,000 compared with that of the conventional mechanical micromanipulator and was installed in a chip. We succeeded in precise positioning of the tool (5 ¿m) with low disturbances. The tool is actuated noncontact by the magnetic force, therefore, the microfluidic chip part is fully disposable with low cost. Of special notes are following. (1) Novel vibrating type of MMT is proposed to reduce the dead band of the magnetic actuation. (2) Omni-directional actuation of the tool was achieved by controlling magnetic field focused on a chip. (3) Backlash of the tool was reduced by supporting it by the flexible hinge with isotropic spring constant. (4) A polymer-metal hybrid structure which has properties of both elasticity and rigidity was employed for the tool. (5) Based on the novel and original design, we integrated a robot-on-a-chip (Robochip) and demonstrated on-chip enucleation of oocyte.