Monolithic Microfabricated Valves and Pumps by Multilayer Soft Lithography

TLDR

Soft lithography uses replica molding of elastomeric materials to fabricate microfluidic stamps and channels, offering an alternative to silicon-based micromachining. The authors aim to extend soft lithography to a multilayer approach, enabling fabrication of multi‑layer soft‑material devices. They employ multilayer soft lithography, a replica‑molding technique that layers elastomeric materials to create multi‑layer microfluidic structures. Using this technique, they built active microfluidic systems with on‑off valves, switching valves, and pumps entirely from elastomer, achieving device areas more than two orders of magnitude smaller than silicon‑based devices while retaining rapid prototyping, ease of fabrication, and biocompatibility.

Abstract

Soft lithography is an alternative to silicon-based micromachining that uses replica molding of nontraditional elastomeric materials to fabricate stamps and microfluidic channels. We describe here an extension to the soft lithography paradigm, multilayer soft lithography, with which devices consisting of multiple layers may be fabricated from soft materials. We used this technique to build active microfluidic systems containing on-off valves, switching valves, and pumps entirely out of elastomer. The softness of these materials allows the device areas to be reduced by more than two orders of magnitude compared with silicon-based devices. The other advantages of soft lithography, such as rapid prototyping, ease of fabrication, and biocompatibility, are retained.