Post modification of injection molded polystyrene components using green solvents and flexible masks

In this paper two novel solvent based molding techniques were developed for the post modification of a selection of injection molded substrates. We will show that a variety of 2- and 3-D designs containing nano and micron size structures can be fabricated on flat, vertical and curved injection molded surfaces using a selection of green solvents in less than 48 h. The novel techniques used thin and thick film masters composed of polydimethylsiloxane and polyester in conjunction with a variety of pure and blended green solvents to modify injection molded polystyrene (PS). Moreover the said techniques allowed us to fabricate novel diffractive structures in injection molded polystyrene via multi-step soft imprint lithography (MSSIL).The new techniques were further validated by molding microfluidics components with integrated features ranging from 0.4 μm to 150 μm on dish in a single step. The effects of residual solvent on the viability and growth of E. coli O157 using grating cuvettes and petri-dishes were also measured and their effect on the hydrophobic recovery time of plasma treated injection molded polystyrene was recorded. We found the majority of the modified cuvettes did not exhibit any antioxidant or antibacterial properties and that the hydrophobic recovery time of oxidized polystyrene surfaces containing residual solvent did not significantly differ from plasma-treated pure polystyrene.