H perfluorooctyl silane

3″ silicon test wafers (University Wafer, Catalog #447, Boston, MA) were rinsed extensively with acetone and isopropyl alcohol, then placed on a hotplate at 300 °C for a minimum of two hours to drive off water. Wafers were then coated with SU8 2025 photoresist (MicroChem Corp., Westborough, MA) and spun on a WS-400-6NPP spin coater (Laurell Technologies Corporation, North Wales, PA) using empirical protocols. After soft bake, photoresist was exposed on a Karl Suss MJB3 mask aligner (Suss MicroTec, Garching bei München, Deutschland) using transparency masks (printed by CAD/Art Services, Bandon, OR) mounted on a quartz slide (Chemglass Life Sciences, Vineland, NJ). Wafers were then post-exposure baked according to MicroChem protocol and developed using SU8 Developer (MicroChem). The thickness of resultant channel masks was confirmed at multiple locations using a NewView 7300 optical profilometer (Zygo Corp., Middlefield, CT), and re-verified after device assembly with fluorescence imaging. To facilitate later release of molded devices, wafers were treated with 1% v/v Trichloro(1 H,1 H,2 H,2H-perfluorooctyl)silane (Sigma-Aldrich Corp., St. Louis, MO) in hexanes for 5–30 minutes, dependent on ambient humidity, at room temperature and washed extensively with isopropyl alcohol before overnight hard bake at 80 °C in a hybridization oven.

Poly(dimethylsiloxane) (Sylgard® 184) was purchased from Dow Corning Corporation (Michigan, USA), and poly(methyl methacrylate) from theplasticshop.co.UK (Coventry, UK). Epoxy adhesive (Yellow Dual Cartridge) was purchased from RS Components Ltd. (Corby, UK). Poly(lactic-co-glycolic acid), Pluronic® F127, dichloromethane, polyoxyethylene (40) stearate, trichloro-(1 H, 1 H, 2 H, 2 H-perfluorooctyl)-silane, and Evans blue dye were purchased from Sigma Aldrich (Gillingham, UK). Phosphate buffered saline was purchased from Life Technologies (Thermo Fisher Scientific Inc., Massachusetts, USA) and 1,2-distearoyl-sn-glycero-3-phosphocholine from Avanti Polar Lipids (Alabama, USA). Perfluorohexane was purchased from Apollo Scientific Ltd. (Stockport, UK). Nitrogen (N₂) gas was provided by The BOC Group plc (Guildford, UK).