Three-dimensional heating and patterning dynamics of particles in microscale acoustic tweezers. Issue 15 (19th July 2022)

• Record Type: Journal Article
• Authors: Weser, Robert; Deng, Zhichao; Kondalkar, Vijay V.; Darinskii, Alexandre N.; Cierpka, Christian; Schmidt, Hagen; König, Jörg
• Is Part Of: Lab on a chip. Volume 22:Issue 15(2022)
• Page Start: 2886
• Page End: 2901
• Publication Date: 2022-07-19
• Subjects: Miniature electronic equipment -- Periodicals; Combinatorial chemistry -- Periodicals; Biotechnology -- Periodicals; 543.0813
• DOI: 10.1039/d2lc00200k
• Languages: English
• ISSNs: 1473-0197

Abstract

Abstract : High-resolution in situ measurements provide deep insights into acoustophoresis induced by surface acoustic waves, revealing the correlation between acoustic fields and 3D particle positions, energy conversion processes and localized heating effects. Abstract : Acoustic tweezers facilitate a noninvasive, contactless, and label-free method for the precise manipulation of micro objects, including biological cells. Although cells are exposed to mechanical and thermal stress, acoustic tweezers are usually considered as biocompatible. Here, we present a holistic experimental approach to reveal the correlation between acoustic fields, acoustophoretic motion and heating effects of particles induced by an acoustic tweezer setup. The system is based on surface acoustic waves and was characterized by applying laser Doppler vibrometry, astigmatism particle tracking velocimetry and luminescence lifetime imaging. In situ measurements with high spatial and temporal resolution reveal a three-dimensional particle patterning coinciding with the experimentally assisted numerical result of the acoustic radiation force distribution. In addition, a considerable and rapid heating up to 55 °C depending on specific parameters was observed. Although these temperatures may be harmful to living cells, counter-measures can be found as the time scales of patterning and heating are shown to be different.