Fabrication of high-aspect-ratio and nonplanar microfluidics using sacrificial 3D printing

Abstract

Traditional microfluidic fabrication relies heavily on photolithography and soft lithography, a process limited by high costs, cleanroom requirements, and planar geometric constraints. Here, we present a rapid, lithography-free fabrication strategy utilizing fused deposition modeling-printed acrylonitrile butadiene styrene as a sacrificial template to create monolithic polydimethylsiloxane devices. By integrating acetone vapor smoothing with selective dissolution, we effectively minimize surface roughness and generate seamless, three-dimensional channels without the need for layer bonding. The versatility of this method is demonstrated through two distinct, geometry-dependent applications: high-aspect-ratio micropillar arrays (10:1 ratio) essential for micro- and nanodevices requiring extended surfaces, and thermoformed curved microchannels (60 μm in height) suitable for smart contact lenses and wearable electronics. This approach bridges the gap between rapid prototyping and functional deployment, offering a scalable solution for fabricating complex, nonplanar microfluidic systems.