Fig. 1

Schematic diagram of a surface acoustic wave particle separation device (color online)"

Fig. 2

(a) Top view of the microdevice. (b) Schematic diagram of the 2D cross-section. Domain C is not included directly in the simulation (color online)"

Table 1

Integral deviations of the inviscid and slip-actuation viscous solutions"

Fig. 3

The deviation of u1 calculated by the inviscid equation from the reference solution, where the dashed area is enlarged in the left graph, and the dark region relates to more than 25% difference"

Fig. 4

The mass source term in the reference solution, where the dashed area is enlarged on the left, and the maximum equals 5.8 kg·m-3·s-1"

Fig. 5

The x-momentum source term in the reference solution, where the dashed area is enlarged on the left, and the maximum equals 3× 105 N·m-3"

Fig. 6

The y-momentum source term in the reference solution, where the dashed area is enlarged on the left, and the maximum equals 4× 105 N·m-3"

Fig. 7

The convergence in terms of lv for 20-80 glycerol-water as the background fluid"

Fig. 8

Deviation from the reference solution in terms of the viscous strip thickness: (a) φ=π (default), (b) φ=0, (c) φ=π/4, and (d) φ=π/2"

Fig. 9

The deviation from the reference solution when nIDT=2 to 18"

Fig. 10

The least deviation from the reference solution around lv=8δ for (a) W=0.5λ, (b) W=0.75λ, (c) W=2λ, (d) W=3λ, and (e) W=4λ, where φ=π"

Fig. 11

The approximation not recommended for the microchannel heights more than half of a wavelength: (a) H=λ/2=300 μm and (b) H=1.5λ=900 μm"

Fig. 12

The evaluation of particle traces for φ=π after 100 s, where the gray and black colors are used for the completely viscous approach and the viscous strip approach, respectively: (a) D=15 μm and (b) D=2 μm. For excellent similarity, the black traces are covered by the gray ones"

Fig. 13

The evaluation of particle traces for φ=0 after 100 s, where the gray and black colors are used for the completely viscous approach and the viscous strip approach, respectively: (a) D=15 μm and (b) D=2 μm. The black traces are covered by the gray ones"

Fig. 14

The evolution of u1 with lv: (a) u1 contours in the reference solution and (b) u1 profiles over the dashed line shown in the contours"