title: Acoustic micro-vortexing of fluids, particles and cells in disposable microfluidic chips.
abstract: 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.
authors.affiliation: Department of Applied Physics, Royal Institute of Technology, KTH-Albanova, SE-106 91, Stockholm, Sweden.
authors.forename: Ida
authors.initials: I
authors.lastname: Iranmanesh
authors.affiliation: Department of Applied Physics, Royal Institute of Technology, KTH-Albanova, SE-106 91, Stockholm, Sweden.
authors.forename: Mathias
authors.initials: M
authors.lastname: Ohlin
authors.affiliation: School of Biotechnology, Royal Institute of Technology, KTH-SciLifeLab, SE-171 21, Solna, Sweden.
authors.forename: Harisha
authors.initials: H
authors.lastname: Ramachandraiah
authors.affiliation: Department of Applied Physics, Royal Institute of Technology, KTH-Albanova, SE-106 91, Stockholm, Sweden.
authors.forename: Simon
authors.initials: S
authors.lastname: Ye
authors.affiliation: School of Biotechnology, Royal Institute of Technology, KTH-SciLifeLab, SE-171 21, Solna, Sweden.
authors.forename: Aman
authors.initials: A
authors.lastname: Russom
authors.affiliation: Department of Applied Physics, Royal Institute of Technology, KTH-Albanova, SE-106 91, Stockholm, Sweden. martin@biox.kth.se.
authors.forename: Martin
authors.initials: M
authors.lastname: Wiklund
mesh_terms: D000072283:A549 Cells; D000162:Acoustics; D006801:Humans; D060526:Magnetic Fields; D046210:Microfluidic Analytical Techniques; D044085:Microfluidics / Q000295:instrumentation*; D011108:Polymers / Q000737:chemistry
chemical_list: D011108:Polymers
keywords: Acoustic streaming; Cell lysis; Lab on a chip