Abstract
Acoustic manipulation of particles in microchannels has recently gained much attention. Ultrasonic standing wave (USW) separation of oil droplets or particles is an established technology for microscale applications. Acoustofluidic devices are normally operated at optimized conditions, namely, resonant frequency, to minimize power consumption. It has been recently shown that symmetry breaking is needed to obtain efficient conditions for acoustic particle trapping. In this work, we study the acoustophoretic behavior of monodisperse oil droplets (silicone oil and hexadecane) in water in the microfluidic chip operating at a non-resonant frequency and an off-center placement of the transducer. Finite element-based computer simulations are further performed to investigate the influence of these conditions on the acoustic pressure distribution and oil trapping behavior. Via investigating the Gor’kov potential, we obtained an overlap between the trapping patterns obtained in experiments and simulations. We demonstrate that an off-center placement of the transducer and driving the transducer at a non-resonant frequency can still lead to predictable behavior of particles in acoustofluidics. This is relevant to applications in which the theoretical resonant frequency cannot be achieved, e.g., manipulation of biological matter within living tissues.
| Original language | English |
|---|---|
| Article number | 064107 |
| Number of pages | 12 |
| Journal | Biomicrofluidics |
| Volume | 17 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2023 |
Funding
We wish to thank Dr. Pengyu Lv [Department of Mechanics and Engineering Science, Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT), College of Engineering, Peking University, Beijing] for invaluable advice and help on PIV and PTV analysis using MATLAB. We would like to also thank Dr. Aura Visan (Group of soft matter, fluidics, and interfaces, University of Twente) for providing the microfluidic chip. R. G. H. Lammertink acknowledges support provided by the Netherlands Organisation for Scientific Research (NWO) for a Vici grant (Project Code No. STW 016.160.312) and Wetsus, European Centre of Excellence for Sustainable Water Technology (www.wetsus.nl). Wetsus is co-funded by the Dutch Ministry of Economic Affairs and Ministry of Infrastructure and Environment, the European Union Regional Development Fund, the Province of Frysl n ^ , and the Northern Netherlands Provinces. The electrical measurements of the chip were carried out using facilities of Wetsus.Funding Information: