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Abstract Acoustic tweezers use ultrasound for contact-free manipulation of particles from millimeter to sub-micrometer scale. Particle trapping is usually associated with either radiation forces or acoustic streaming fields. Acoustic tweezers based on single-beam focused acoustic vortices have attracted considerable attention due to their selective trapping capability, but have proven difficult to use for three-dimensional (3D) trapping without a complex transducer array and significant constraints on the trapped particle properties. Here we demonstrate a 3D acoustic tweezer in fluids that uses a single transducer and combines the radiation force for trapping in two dimensions with the streaming force to provide levitation in the third dimension. The idea is demonstrated in both simulation and experiments operating at 500 kHz, and the achieved levitation force reaches three orders of magnitude larger than for previous 3D trapping. This hybrid acoustic tweezer that integrates acoustic streaming adds an additional twist to the approach and expands the range of particles that can be manipulated.
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Lifting, Selective Trapping, and Moving of Single Microparticle with Electrical Signal on Multi-Foci-Fresnel Acoustic Transducer
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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- Award ID(s):
- 2129856
- PAR ID:
- 10478422
- Publisher / Repository:
- IEEE
- Date Published:
- Journal Name:
- The 37th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2024)
- Subject(s) / Keyword(s):
- Acoustic Tweezers, Contactless Microparticle Trapping, Acoustic Radiation Force, Particle Delivery
- Format(s):
- Medium: X
- Location:
- Austin, TX
- Sponsoring Org:
- National Science Foundation
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