TY - JOUR
T1 - Motile cells as probes for characterizing acoustofluidic devices
AU - Kim, Minji
AU - Bayly, Philip V.
AU - Meacham, J. Mark
N1 - Funding Information:
This work was supported by the NSF (Grant No. CMMI-1633971 and CBET-1944063). MK was partially funded by the Spencer T. and Ann W. Olin Fellowship for Women in Graduate Study. The authors acknowledge partial financial support from Washington University in St. Louis and the Institute of Materials Science and Engineering for the use of fabrication instruments and staff assistance. The authors would also like to thank Mathieu Bottier and Susan K. Dutcher for providing C. reinhardtii cells.
Publisher Copyright:
© The Royal Society of Chemistry 2021.
PY - 2021/2/7
Y1 - 2021/2/7
N2 - Acoustic microfluidics has emerged as a versatile solution for particle manipulation in medicine and biology. However, current technologies are largely confined to specialized research laboratories. The translation of acoustofluidics from research to clinical and industrial settings requires improved consistency and repeatability across different platforms. Performance comparisons will require straightforward experimental assessment tools that are not yet available. We introduce a method for characterizing acoustofluidic devices in real-time by exploiting the capacity of swimming microorganisms to respond to changes in their environment. The unicellular alga,Chlamydomonas reinhardtii, is used as an active probe to visualize the evolving acoustic pressure field within microfluidic channels and chambers. In contrast to more familiar mammalian cells,C. reinhardtiiare simple to prepare and maintain, and exhibit a relatively uniform size distribution that more closely resembles calibration particles; however, unlike passive particles, these motile cells naturally fill complex chamber geometries and redistribute when the acoustic field changes or is turned off. In this way,C. reinhardtiicells offer greater flexibility than conventional polymer or glass calibration beads forin situdetermination of device operating characteristics. To illustrate the technique, the varying spatial density and distribution of swimming cells are correlated to the acoustic potential to automatically locate device resonances within a specified frequency range. Peaks in the correlation coefficient of successive images not only identify the resonant frequencies for various geometries, but the peak shape can be related to the relative strength of the resonances. Qualitative mapping of the acoustic field strength with increasing voltage amplitude is also shown. Thus, we demonstrate that dynamically responsiveC. reinhardtiienable real-time measurement and continuous monitoring of acoustofluidic device performance.
AB - Acoustic microfluidics has emerged as a versatile solution for particle manipulation in medicine and biology. However, current technologies are largely confined to specialized research laboratories. The translation of acoustofluidics from research to clinical and industrial settings requires improved consistency and repeatability across different platforms. Performance comparisons will require straightforward experimental assessment tools that are not yet available. We introduce a method for characterizing acoustofluidic devices in real-time by exploiting the capacity of swimming microorganisms to respond to changes in their environment. The unicellular alga,Chlamydomonas reinhardtii, is used as an active probe to visualize the evolving acoustic pressure field within microfluidic channels and chambers. In contrast to more familiar mammalian cells,C. reinhardtiiare simple to prepare and maintain, and exhibit a relatively uniform size distribution that more closely resembles calibration particles; however, unlike passive particles, these motile cells naturally fill complex chamber geometries and redistribute when the acoustic field changes or is turned off. In this way,C. reinhardtiicells offer greater flexibility than conventional polymer or glass calibration beads forin situdetermination of device operating characteristics. To illustrate the technique, the varying spatial density and distribution of swimming cells are correlated to the acoustic potential to automatically locate device resonances within a specified frequency range. Peaks in the correlation coefficient of successive images not only identify the resonant frequencies for various geometries, but the peak shape can be related to the relative strength of the resonances. Qualitative mapping of the acoustic field strength with increasing voltage amplitude is also shown. Thus, we demonstrate that dynamically responsiveC. reinhardtiienable real-time measurement and continuous monitoring of acoustofluidic device performance.
UR - http://www.scopus.com/inward/record.url?scp=85100814989&partnerID=8YFLogxK
U2 - 10.1039/d0lc01025a
DO - 10.1039/d0lc01025a
M3 - Article
C2 - 33507201
AN - SCOPUS:85100814989
SN - 1473-0197
VL - 21
SP - 521
EP - 533
JO - Lab on a Chip
JF - Lab on a Chip
IS - 3
ER -