Multifunctional Noncontact Micromanipulation Using Whirling Flow Generated by Vibrating a Single Piezo Actuator

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2019-02, Vol.15 (5), p.e1804421-n/a
• Main Authors: Liu, Xiaoming, Shi, Qing, Lin, Yuqing, Kojima, Masaru, Mae, Yasushi, Fukuda, Toshio, Huang, Qiang, Arai, Tatsuo
• Format: Article
• Language: English
• Subjects: Flow velocity; Fluid flow; Low pressure; Micromanipulation; Nanoparticles; Nanotechnology; piezo actuator; Piezoelectric actuators; Rotating spheres; Rotation; Velocity gradient; Vibration; whirling flow
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201804421

A noncontact method that can achieve immobilization, transportation, and rotation in the microscale is desired in biological micromanipulation. A multifunctional noncontact micromanipulation method is proposed here based on a vibration‐generated whirling flow. Resonance of a cantilever structure is utilized to extend the straight vibration of a single piezo actuator to the 2D circular vibration of a micropipette. The circular vibration in fluids can generate the whirling flow featured with low pressure in the core area and flow velocity gradient. The low pressure can immobilize the objects nearby and transport them together with the micropipette, and the flow velocity gradient is utilized to form a torque to rotate the immobilized object. Experiments of the microbeads are conducted to evaluate the claimed functions and quantify the key parameters that influence the rotation velocity. The cell spheroid is immobilized and rotated for 3D observation, and by assessing the viability of the cells containing in the spheroid, the proposed method is proved noninvasive to living cells. Finally, another important application in operations of mouse egg cells is shown, which indicates that the proposed method is a potential valuable tool in biological micromanipulation. A multifunctional noncontact micromanipulation method is desired in biological fields. Resonance is utilized to extend a piezo actuator's straight vibration to a micropipette's 2D circular vibration, which can generate a whirling flow in fluids. Low pressure in its core area can immobilize the objects and transport them with the micropipette. The flow velocity gradient is utilized to rotate the immobilized object.