Volumetric Additive Manufacturing of Silica Glass with Microscale Computed Axial Lithography

TL;DR

This paper presents microscale computed axial lithography (micro-CAL), a novel high-speed 3D printing method for creating complex, high-strength silica glass microstructures with fine features and smooth surfaces, expanding manufacturing possibilities.

Contribution

Introduction of micro-CAL, a layer-free digital light manufacturing process capable of fabricating complex silica glass microstructures with high precision and geometric freedom.

Findings

Fabricated microfluidics with 150 μm internal diameters

Produced micro-optical elements with 6 nm surface roughness

Created complex high-strength lattice structures with 50 μm features

Abstract

Glass is increasingly desired as a material for manufacturing complex microscopic geometries, from the micro-optics in compact consumer products to microfluidic systems for chemical synthesis and biological analyses. As the size, geometric, surface roughness, and mechanical strength requirements of glass evolve, conventional processing methods are challenged. We introduce microscale computed axial lithography (micro-CAL) of fused silica components, by tomographically illuminating a photopolymer-silica nanocomposite which is then sintered. We fabricated 3D microfluidics with internal diameters of 150 micrometers, freeform micro-optical elements with surface roughness of 6 nm, and complex high-strength trusses and lattice structures with minimum feature sizes of 50 micrometers. As a high-speed, layer-free digital light manufacturing process, micro-CAL can process extremely viscous nanocomposites with high geometric freedom, enabling new device structures and applications.