Acoustic micro-vortexing of fluids, particles and cells in disposable microfluidic chips

• Published in: Biomedical microdevices Vol. 18; no. 4; pp. 71 - 7
• Main Authors: Iranmanesh, Ida, Ohlin, Mathias, Ramachandraiah, Harisha, Ye, Simon, Russom, Aman, Wiklund, Martin
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2016; Springer Nature B.V
• Subjects: A549 Cells; Acoustic streaming; Acoustics; Biological and Medical Physics; Biomedical Engineering and Bioengineering; Biomedical research; Biophysics; Cell lysis; Cellular biology; Chips; Computational fluid dynamics; Deoxyribonucleic acid; Engineering; Engineering Fluid Dynamics; Extraction; Fluids; Humans; Lab on a chip; Magnetic Fields; Mathematical models; Microfluidic Analytical Techniques; Microfluidics; Microfluidics - instrumentation; Nanotechnology; Polymers; Polymers - chemistry; Transducers; Cell lysis; Lab on a chip; Acoustic streaming
• ISSN: 1387-2176; 1572-8781; 1572-8781
• DOI: 10.1007/s10544-016-0097-4

We demonstrate an acoustic platform for micro-vortexing in disposable polymer microfluidic chips with small-volume (20 μl) reaction chambers. The described method is demonstrated for a variety of standard vortexing functions, including mixing of fluids, re-suspension of a pellet of magnetic beads collected by a magnet placed on the chip, and lysis of cells for DNA extraction. The device is based on a modified Langevin-type ultrasonic transducer with an exponential horn for efficient coupling into the microfluidic chip, which is actuated by a low-cost fixed-frequency electronic driver board. The transducer is optimized by numerical modelling, and different demonstrated vortexing functions are realized by actuating the transducer for varying times; from fractions of a second for fluid mixing, to half a minute for cell lysis and DNA extraction. The platform can be operated during 1 min below physiological temperatures with the help of a PC fan, a Peltier element and an aluminum heat sink acting as the chip holder. As a proof of principle for sample preparation applications, we demonstrate on-chip cell lysis and DNA extraction within 25 s. The method is of interest for automating and chip-integrating sample preparation procedures in various biological assays.