Figure 3.

Pictures of particle clusters captured and retained in the multinodal acoustic trap. The flow rate in all pictures is 500 μL/min. (A) Bright-field image of the seed particle clusters viewed from the top. (B) Seed particle cluster viewed from the side. (C) Fluorescence image of a seed particle cluster enriched with 500 nm fluorescent polystyrene particles, viewed from the top. White dashed lines indicate the transducer. (D) Seed particle cluster enriched with 500 nm fluorescent polystyrene particles, viewed from the side. Blue dashed lines indicate the capillary wall. In both (B) and (D), nine clusters of particles can be seen stacked vertically above the transducer. The transducer is located at the top of the picture. The curved edges of the capillary cause optical distortions close to the wall, making the clusters appear more smeared.