Flow-free transport of cells in microchannels by frequency-modulated ultrasound.
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.
Manneberg
O
O
Department of Applied Physics, Royal Institute of Technology, AlbaNova University Center, SE-106 91, Stockholm, Sweden.
Vanherberghen
B
B
Onfelt
B
B
Wiklund
M
M
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