High-precision motion of magnetic microrobot with ultrasonic levitation for 3-D rotation of single oocyte

Abstract

In this study, we propose an innovative driving method for a microrobot. By using acoustic levitation, the microrobot can be levitated from the glass substrate. We are able to achieve positioning accuracy of less than 1 μm, and the response speed and output force are also significantly improved. Silicon-based microrobots can be made into diverse shapes using deep reactive-ion etching (DRIE). Using custom-designed microrobots allows for the 3-D rotational control of a single bovine oocyte. Orientation with an accuracy of 1° and an average rotation velocity of 3 rad/s are achieved. This study contributes to the biotechnology. In the study of oocytes/embryos, manipulation is used for the enucleation, microinjection, and investigation of the characteristics of oocytes, such as the meiotic spindle and zona pellucida using PolScope. These studies and their clinical applications involve the three-dimensional (3-D) rotation of mammalian oocytes. The overall out-of-plane and in-plane rotations of the oocyte are demonstrated by using an acoustically levitated microrobot. In addition, by using this approach, it becomes much easier to manipulate the cell to investigate the characteristics of the single cell and analyze its mechanical properties.