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This paper presents the mixing, trapping, and ejection of a single microparticle based on an acoustic tweezers. Finite Element Model (FEM) simulation, along with analytical modeling, is used to study the selectivity of particles based on size and material properties. The acoustic tweezers is optimized to have a single trapping zone, where particles are trapped due to acoustic radiation force (which is calculated for particle sizes exceeding the Rayleigh approximation). The tweezers is experimentally shown to lift microparticles from the tweezers surface, selectively trap a single particle based on size and material acoustic properties, and then eject it upwards for collection. All these are obtained with negligible heat generation.
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Ring-shaped photoacoustic tweezers for single particle manipulation
This Letter reports ring-shaped photoacoustic (PA) tweezers that are capable of manipulating single or multiple micron-sized particles. By illuminating a thin layer of an optically absorptive liquid medium with a focused annular pulsed laser beam and a higher pulse repetition rate (e.g., 800 Hz), both acoustic radiation force and instantaneous vaporization repulsion are generated within a certain distance of the illumination region. This makes it possible to conduct continuous and versatile locomotion of single or multiple microparticles. In this Letter, interactions between two or more particles are demonstrated, such as separation, attachment, and grouping of microparticles. The PA tweezers combine some of the advantages of conventional optical and acoustic tweezers and are expected to be a useful alternative approach for the manipulation of microscale objects.
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- PAR ID:
- 10368642
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Letters
- Volume:
- 47
- Issue:
- 4
- ISSN:
- 0146-9592; OPLEDP
- Format(s):
- Medium: X Size: Article No. 826
- Size(s):
- Article No. 826
- Sponsoring Org:
- National Science Foundation
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