printers might be able to print the microfluidic channel directly

without binding the channel to another substrate [15]. The

method we described here has lower requirement of expertise

and printer resolution, making the device more accessible to

general laboratories.

4. In general, syringe pump is less preferred for this application

due to the fast deposition of microcarriers and noncontinuous

manner of separation in large-scale.

5. The SLA printer recommended for this purpose is Formlab

form 3, and the DLP printer recommended is MIICRAFT.

Higher printing resolution gives smoother geometry. Rough

surface of the device and mold will disrupt the flow and affect

the separation efficiency of the device.

6. The inlet of the direct-printed chip was placed at a 60
angle to

prevent blockage of microcarriers. The inlet and outlet sizes of

Fig. 3 The separation results of the PDMS-made device. (a) The separated microcarriers from the inner outlet

and (b) harvested cells from the outer outlet respectively. The scale bar is 200 μm. (c) The viability of cells

after running through the device under the high flow rate of 30 mL/min shows no significant drop even after

two rounds of separation. (d) The cells were showed to preserve their differentiation potential by trilineage

differentiation. (Reproduced from [12] with permission from Nature)

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