240
G. Feng et al.
Fig. 7.29 SEM images of net-like microfluidic channels after selective chemical etching. a Overall
profile; b an enlarged image of the microfluidic channel when focus is located on the substrate
surface; c an enlarged image of the microfluidic channel when focus is located at the bottom of a
microfluidic channel [47]
The width of networked microfluidic channel measured at different straight
channel is shown in Fig. 7.30, and each data point is the result of the average of
five values measured at different positions of the same straight channel. Figure 7.30a
is the width of networked microfluidic channel before etching. Obviously, the width
of microfluidic channel is about 7.25 μm. Figure 7.30b is the width of networked
microfluidic channel after etching, and the width of microfluidic channel is about
8.25 μm. Apparently, etching process increases the width of microfluidic channel
about 1 μm. In addition, according to date point and corresponding error distribution,
global and regional of microfluidic channel both become more homogeneous after
etching.
Fig. 7.30 Width of networked microfluidic channel at different straight channel: a before etching
and b after etching [47]