Noncontact 3-D Orientation Control at Microscale: Hydrodynamic Out-of-Plane Rotation and In-Plane Rotation by Compacted Rotational Stage

Abstract

In cloning, clinical <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vitro</i> fertilization, gene research, and stem cell research, enucleation or injection of the individual cell is essential. Three-dimensional (3-D) orientation control of the target cell could significantly influence the operation success rate, which is still one of the main challenges in conventional micromanipulation. In this article, we give a cost-effective solution of the 3-D orientation control at the microscale combining the hydrodynamic out-of-plane rotation and the in-plane rotation by compacted rotational stage. We equipped a standard microinjection system with a single piezo-actuator and a 3-D printed compacted rotational stage. Using the resonance of the designed copper cantilever as the pipette holder and the Lissajous Principle, we extended the 1-D oscillation of the piezo-actuator to 2-D circular oscillation of the injecting micropipette. The circular oscillation could generate a whirling flow for noncontact immobilization and out-of-plane rotation of the target. After the out-of-plane rotation, the rotational stage was employed to realize the in-plane rotation, and a holding-position control strategy was proposed to compensate circular motion in global of the target. The performance of these two rotation methods has been tested by rotating microbeads with outer diameters of 98 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</i> m. 3-D orientation control of the microbead and the mouse oocyte has been achieved, which indicates that the proposed method could be widely applied in the biomedical field.