Rapid prototyping of microfluidic multi-scale lab-on-a-foil devices in COC

Developing scalable and cost-effective fabrication methods for microfluidic lab-on-a-chip devices is critical to bridging the gap between rapid prototyping and mass production. We present a rapid and affordable prototyping method for lab-on-a-foil devices with multi-scale fluidic features ranging from picoliters (features size: 20 µm) to microliters (feature size: 100–1500 µm). Our three-step approach — thermoforming, hot embossing, and thermal sealing - enables the co-integration of picoliter wells with nano- to microliter channels and chambers using cyclic olefin copolymer (COC), a thermoplastic polymer suitable for scalable manufacturing without requiring additional surface treatments. This method overcomes the limitations of non-scalable polydimethylsiloxane (PDMS) prototyping and the high initial cost of thermoplastic injection molding. With low tooling costs, rapid turnaround times, and material compatibility with high-precision mass production, this technique offers an efficient pathway for the development of multi-scale lab-on-a-chip devices for applications such as digital PCR and solid phase extraction.