Rapid Multi-Material Direct Laser Writing

Abstract

The additive manufacturing or “three-dimensional (3D) printing” technology direct laser writing (DLW) offers a level of geometric versatility at submicron scales that yields substantial benefits for fields including photonics, meta-materials, and 3D cell biology. A key limitation of DLW, however, stems from the difficulties in 3D printing micro/nanoscale structures with more than a single material. Specifically, producing multi-material components requires laborious and time-intensive protocols for manual substrate/material processing and alignment to maintain structural continuity among distinct photomaterials. To overcome these challenges, here we introduce a “rapid multi-material DLW (RMM-DLW)” strategy that enables 3D nanostructured features comprised of multiple, fully integrated photomaterials to be additively manufactured with unprecedented speed and accuracy. This approach leverages an impermanent elastomeric bonding technique to achieve temporary microchannels through which distinct photomaterials can be serially loaded, photopolymerized, and developed; the elastomer can be removed thereafter. Preliminary RMM-DLW results revealed a 74% reduction in fabrication time, with a multi-material alignment accuracy of $0.14\pm 0.17 \mu \mathrm{m} (\Delta \mathrm{X})$ and $0.20\pm 0.15 \mu \mathrm{m} (\Delta \mathrm{Y})$ - an improvement of up to one order of magnitude over conventional multi-material DLW. In combination, these results suggest a promising pathway to achieve fundamentally new classes of multi-material, and in turn, multi-functional 3D nanostructured systems.