Ultra rapid low cost microfabrication process for biomedical tools

The advent of microfluidics technology has led to many innovative advancements in the fields of science and engineering, most notably through its improvements in the unit operations of chemical processes as well as biological detection and point of care (POC) diagnostics. However, current microfabrication methods, such as photolithography, hot embossing, and thin film deposition, typically necessitate investments in expensive capital equipment and extensive processing steps, thus limiting their use to a few highly specialized laboratories with the necessary infrastructure. To circumvent this problem, we have developed a novel microfabrication technique which allows for the high resolution patterning and rapid prototyping of functional microfluidic devices from thermoplastics. By leveraging the heat-induced shrinkage properties of pre-stressed thermoplastics such as polystyrene (PS) and polyolefins (PO), microfluidic patterns can be directly printed and etched onto the substrates, and subsequently ‘shrunk’ to generate high-aspect microfeatures. Thus, by printing on the macroscale and shrinking to generate high resolution patterns, we negate the use of expensive tooling devices. Further, to demonstrate the utility of this process, we have fabricated a high throughput stem cell culture platform comprising of closely packed (honeycomb) arrays of microwells as well as microfluidic devices capable of performing size-dependent separation processes, and immunosorbent assays.