title: Flow-free transport of cells in microchannels by frequency-modulated ultrasound.
abstract: We demonstrate flow-free transport of cells and particles by the use of frequency-modulated ultrasonic actuation of a microfluidic chip. Two different modulation schemes are combined: A rapid (1 kHz) linear frequency sweep around approximately 6.9 MHz is used for two-dimensional spatial stabilization of the force field over a 5 mm long inlet channel of constant cross section, and a slow (0.2-0.7 Hz) linear frequency sweep around approximately 2.6 MHz is used for flow-free ultrasonic transport and positioning of cells or particles. The method is used for controlling the motion and position of cells monitored with high-resolution optical microscopy, but can also be used more generally for improving the robustness and performance of ultrasonic manipulation micro-devices.
authors.affiliation: Department of Applied Physics, Royal Institute of Technology, AlbaNova University Center, SE-106 91, Stockholm, Sweden.
authors.forename: O
authors.initials: O
authors.lastname: Manneberg
authors.forename: B
authors.initials: B
authors.lastname: Vanherberghen
authors.forename: B
authors.initials: B
authors.lastname: Onfelt
authors.forename: M
authors.initials: M
authors.lastname: Wiklund
mesh_terms: D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D007694:Killer Cells, Natural; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods; D011846:Radio Waves; D014465:Ultrasonics