Issue 15, 2022

Optical feedback control loop for the precise and robust acoustic focusing of cells, micro- and nanoparticles

Abstract

Despite a long history and the vast number of applications demonstrated, very few market products incorporate acoustophoresis. Because a human operator must run and control a device during an experiment, most devices are limited to proof of concepts. On top of a possible detuning due to temperature changes, the human operator introduces a bias which reduces the reproducibility, performance and reliability of devices. To mitigate some of these problems, we propose an optical feedback control loop that optimizes the excitation frequency. We investigate the improvements that can be expected when a human operator is replaced for acoustic micro- and nanometer particle focusing experiments. Three experiments previously conducted in our group were taken as a benchmark. In addition to being automatic, this resulted in the feedback control loop displaying a superior performance compared to an experienced scientist in 1) improving the particle focusing by at least a factor of two for 5 μm diameter PS particles, 2) increasing the range of flow rates in which 1 μm diameter PS particles could be focused and 3) was even capable of focusing 600 nm diameter PS particles at a frequency of 1.72075 MHz. Furthermore, the feedback control loop is capable of focusing biological cells in one and two pressure nodes. The requirements for the feedback control loop are: an optical setup, a run-of-the-mill computer and a computer controllable function generator. Thus resulting in a cost-effective, high-throughput and automated method to rapidly increase the efficiency of established systems. The code for the feedback control loop is openly accessible and the authors explicitly wish that the community uses and modifies the feedback control loop to their own needs.

Graphical abstract: Optical feedback control loop for the precise and robust acoustic focusing of cells, micro- and nanoparticles

Supplementary files

Article information

Article type
Paper
Submitted
24 Apr. 2022
Accepted
08 Jūl. 2022
First published
11 Jūl. 2022
This article is Open Access
Creative Commons BY-NC license

Lab Chip, 2022,22, 2810-2819

Optical feedback control loop for the precise and robust acoustic focusing of cells, micro- and nanoparticles

C. L. Harshbarger, M. S. Gerlt, J. A. Ghadamian, D. C. Bernardoni, J. G. Snedeker and J. Dual, Lab Chip, 2022, 22, 2810 DOI: 10.1039/D2LC00376G

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements