Flow-free transport of cells in microchannels by frequency-modulated ultrasound.

Research paper by O O Manneberg, B B Vanherberghen, B B Onfelt, M M Wiklund

Indexed on: 04 Mar '09Published on: 04 Mar '09Published in: Lab on a Chip


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.