Manipulation of a Micro-Object Using Topological Hydrodynamic Tweezers
Abstract
Manipulating microscale object plays a paramount role in a wide range of fundamental research efforts and applications. At the microscale, various methods have been developed in the past decades, including optical, electric, magnetic, aerodynamic, and acoustic methods. However, these noncontact forces are susceptible to external disturbance, and so finding a way to make microscale object manipulation immune to external perturbations is challenging and remains elusive. Here, we demonstrate a method based on a trapping mechanism to manipulate a microscale object in a gas flow at ambient conditions. We first show that the microdroplet is entrapped in a trapping ring constructed by a particular toroidal vortex. The vortex works as tweezers to control the position of the microdroplet. We then show that the microdroplet can be transported along the trapping ring. By virtue of the topological character of the gas flow, the transport path is able to bypass external strong perturbations automatically. We further demonstrate a topological transfer process of the microdroplet between two hydrodynamic tweezers. Our method provides an integrated toolbox to manipulate a microscale object, with an intrinsic mechanism that protects the target object from external disturbances.
- Publication:
-
Physical Review Applied
- Pub Date:
- October 2019
- DOI:
- 10.1103/PhysRevApplied.12.044017
- arXiv:
- arXiv:1909.08265
- Bibcode:
- 2019PhRvP..12d4017Y
- Keywords:
-
- Physics - Fluid Dynamics;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Physics - Applied Physics
- E-Print:
- 7pages, 5 figures. Accepted by Phys. Rev. Applied