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Updated: Jan 23, 2026

Fabrication, Operation and Flow Visualization in Surface-acoustic-wave-driven Acoustic-counterflow Microfluidics
Published on: August 27, 2013
Traveling surface acoustic wave (TSAW) microfluidic fluorescence activated cell sorter (μFACS)
K Mutafopulos1, P Spink, C D Lofstrom
1School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. weitz@seas.harvard.edu.
Abstract:
We report a microfluidic fluorescence activated cell-sorting (μFACS) device that employs traveling surface acoustic waves (TSAW) to sort cells at rates comparable to conventional jet-in-air FACS machines, with high purity and viability. The device combines inertial flow focusing and sheath flow to align and evenly space cells, improving the sorting accuracy and screening rate. We sort with an interdigital transducer (IDT) whose tapered geometry allows precise positioning of the TSAW for optimal cell sorting. We sort three different cell lines at several kHz, at cell velocities exceeding one meter per second, while maintaining both sorting purity and cell viability at around 90% simultaneously.
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