Better shrinkage than Shrinky-Dinks.

Polyolefins are finding increased popularity in microfluidic applications due to their attractive mechanical, processing, and optical properties. While intricate features are typically realized in these thermoplastics by hot embossing and injection molding, such fabrication approaches are expensive and slow. Here, we apply our shrink-induced approach-first demonstrated with polystyrene 'Shrinky-Dink' sheets-to create micro- and nanostructures with cross-linked polyolefin thin films. These multi-layered films shrink by 95% and with greater uniformity than the Shrinky-Dinks. With such significant reduction in size, along with attractive material properties, such commodity films could find important applications in low cost microfluidic prototyping as well as in point-of-care diagnostics. In this technical note, we demonstrate the ability to rapidly and easily create unique microstructures, increase microarray feature density, and even induce self-assembled integrated metallic nanostructures with these shrink wrap films.