Figure 2.

Numerical simulation of various microchannel dimensions and acoustic field in the cross‐section of the microchannel. a) The sweep of the of the maximum acoustic pressure against the dimensions of the height and width of the microchannel. The three insets in (b) show the acoustic pressure and streaming pattern for the three different channel heights with the same channel width of 200 µm. The PN is indicated by the blue oval, and the acoustic streaming direction is indicated by the black arrows. c.I) The acoustic pressure and streaming pattern for the dimension of 60 µm (height) 200 µm (width), which indicates two PN formed within the microchannel. Two cell traces formation after SAW excitation shows a good agreement with the two PNs. c.II) The zoom‐in simulation of the half microchannel dimension indicates the formation of streaming vortexes around the PN. The coexistence of the PN and streaming will lead to cell rotation in situ along the PN. The red arrows indicate the direction of regional streaming vortexes. Scale bar, 20 µm.