Accurate releasing of biological cells using two release methods generated by high speed motion of an end effector

The reliable manipulation of micro-objects has been a still difficult work in scientific and technical field due to scale effects. This paper presents two types of release methods, using local stream and inertia force generated by 3D high speed motion of an end effector, for releasing and accurate positioning of biological cells. Two-fingered microhand driven by DC motors for both end effectors and PZT actuators for right end effector is employed. A parallel mechanism controlled by three PZT actuators generates 3D high speed motions to release cells adhered to one of the end effector. The local stream and inertia force created by high speed motion of the right end effector detach the cells adhered to the left end effector and right end effector, respectively. To generate the necessary external forces for separation of the attached cells, the vibration having high frequency and suitable amplitude is applied. For accurate positioning of the object, circular motions are proposed. To verify the advantage of the proposed motion, we compare five motions, three 1D motions and two circular motions. Experiments were conducted employing 16μm NIH3T3 cells. From these analyses of experiments, we conclude that the proposed motions can detach micro objects (100%) with high position accuracy (3±0.7μm) on desired position after release.