Single layer (PDMS chip) fabrication
Updated 10/28/2022 02:54 PM
Introduction
Materials
- Silicone Elastomer Kit (SYlgard 184)
- Curing Agent
- Vacuum Desiccator
- Vacuum Pump
- Spin Coater
- Regular Oven
- Air Gun
- Petri Dishes made of glass
- Sterile Disposable Scalpels
- Aluminium Foil
- Scotch Crystal Tape (19mm x 32.9m)
- Conical Tubes (falcon) - 50mL
- Pasteur Pipettes Plastic - 5mL
- 0.8mm hole punch or syringe
- Tweezers
Procedure
Fabrication
- Very carefully pour 40mL PDMS elastomer from its container into a 50mL falcon and then using a plastic pasteur pipette add 8mL curing agent into the falcon (ratio 5:1). For a complete chip, applicable volumes are 5:1 for the control layer and 20:1 for the flow layer.
- Cap the falcon with its lid and mix them really well for 2-3 min
- Using tweezers hold the control layer (wafer/mold) from its edges avoiding the designs and use an air gun to clean it
- Place it into an aluminum foil (or first into a Petri dish made of glass with a satiflying diameter and then into an aluminum foil)
- Place the aluminum foil with the wafer on a straight surface and pour the PDMS mixture on top of the wafer
- Degas mixture for approximately 25 min inside the vacuum desiccator using a vacuum pump
- Preheat the oven at 90oC for 5 min
- Using the oven pan place the PDMS control layer on the mid floor inside the oven and bake it at 90oC for 30 min (make sure that the surface is straight)
- Remove from the oven and using a sharp scalpel cut out the two PDMS designs
- Place the two designs on a clean surface preferably with holes on it and then create holes for inlets and outlets using a 0.8 mm hole puncher or a syringe (penetrate all the way through the PDMS device)
- Protect PDMS surfaces from dust using scotch tape and store them in a clean Petri dish
During this procedure you need to make sure that your working place (PDMS lab) is very clean and avoid any distractions in order to not contaminate your materials. Try to minimize the interactions with your colleagues and always wear gloves and a mask. This protocol is about the fabrication of a chip design (flow or control layer) for quick testing.