5. Double-sided adhesive tape (AR clear, adhesive biotech).

6. Polymethyl methacrylate (PMMA) sheet (see Note 3).

7. Scotch tape for cleaning the printed chip.

8. Air nozzle or hairdryer.

2.2

PDMS Device

Making (in

Replacement of Direct-

Printed Device)

1. Trichloro(1H, 1H, 2H, 2H-perfluoro-octyl)silane to treat the

surface of the mold, for easier device peel off.

2. Polydimethylsiloxane (PDMS), a biocompatible material for

chip fabrication.

3. 45
C oven for PDMS solidification.

4. 3 mm Biopsy punches for making holes in the PDMS devices.

5. 1/16⁰⁰ Rubber tubing (Tygon ND-100-65, USA) for introdu-

cing samples into and out of the device.

2.3

Cell Harvesting

1. 70% ethanol.

2. Dulbecco’s phosphate-buffered saline (DPBS).

3. Digestive enzyme (TrypLE express, Gibco, Invitrogen).

4. Syringe pump (see Note 4).

5. 50 mL disposable syringe.

6. Silicone tubing (inner diameter: 0.50⁰⁰, outer diameter: 0.90⁰⁰).

7. Syringe tips (0.50⁰⁰ Long Tip, Adhesive Dispensing Ltd., match

the size of tubes).

8. Biosafety cabinet.

9. 50 mL falcon tubes.

10. Peristaltic pump (in replacement of syringe pump).

11. Rubber tube (in replacement of Tygon tubes).

3

Methods

3.1

Device Design

Design the spiral microfluidic channels with CAD software (e.g.,

AutoCAD, Solidworks), export the “.Stl” file. Proceed the file in

the printer software for slicing and covert to printing file and set to

print (see Note 5).

For direct printed device, the spiral design is consisted of

6 revolutions, 1.7 pitches, 550 μm inner wall height, 620 μm

outer wall height and 1100 μm width inward trapezoidal spiral

microchannel (see Note 6). For mold fabrication, the mold of the

spiral was designed as an outward spiral with 5 revolutions, 500 μm

inner wall height, 650 μm outer wall height and 4000 μm width

trapezoidal spiral, the pitch of the Archimedean spiral was 7 mm

(3 mm interval between successive spiral loops) [12]. Depending

260

Lin Ding et al.