4.2.1. Preparation of perfluoropolyether (PFPE) mold
The PFPE resin (Fluorolink MD700, Solvay Solexis, Milan, Italy) was
mixed with 3% w/w photoinitiator (Darocur 1173, Sigma Aldrich, St.
Louis, MO, USA) to create the UV-curable resin. Then, the patterned
silicon substrate (e.g., Si master) was coated with the UV-curable resin
and covered with polyethylene terephthalate (PET) film as a backplane.
The PET film was then rolled over to the UV-curable resin to distribute
it evenly and the mixture was cross-linked by exposure to UV light at
365 nm for 5 minutes. After the curing process, the PFPE mold was
detached from the Si master.