Enhanced Gigahertz Acoustofluidic Chip for High-throughput Nanoscale Bioparticle Separation

Acoustic microfluidic separation techniques are suitable for nanoscale particle separation in the biomedical field. However, limited sample throughput and processing speed would make it infeasible to process clinical-scale samples (>500 million cells). Previous studies have shown that the throughput can be initially improved by designing a bulk acoustic wave (BAW) resonator array. In this work, we optimized the design of a 6×6 BAW array chip to achieve the expansion of the array. In addition, a novel wide bandwidth 36-channel power divider is designed to feed the array based on the stripline principle. The low return-loss power divider realizes a more reasonable power distribution method, and combined with the expanded array BAW chip, it significantly improves the throughput. Experimental results show that the chip achieves efficient separation at 80 μL/min throughput, which is 2.7x higher than previous results. In addition, size-dependent separation of nanoparticles can be realized based on the difference in capture efficiency.