Additive Manufacturing of Transparent Silica Glass from Solutions

Abstract

A sol, aqueous solution-based ink is presented for fabrication of 3D transparent silica glass objects with complex geometries, by a simple 3D printing process conducted at room temperature. The ink combines a hybrid ceramic precursor that can undergo both the photopolymerization reaction and a sol-gel process, both in the solution form, without any particles. The printing is conducted by localized photopolymerization with the use of a low-cost 3D printer. Following printing, upon aging and densifying, the resulting objects convert from a gel to a xerogel and then to a fused silica. The printed objects, which are composed of fused silica, are transparent and have tunable density and refractive indices.

Freeform Microfluidic Networks Encapsulated in Laser‐Printed 3D Macroscale Glass Objects

“…However, fabrication of freeform 3D hollow microchannels in fused silica is still difficult for current 2D fabrication techniques in terms of complex and tedious fabrication procedures, additional costs for aligning, stacking, and bonding steps. [27] Meanwhile, 3D printing of glass materials emerging in recent years brings some new opportunities for scalable fabrication of freeform glass structures by either additive manufacturing strategies [28][29][30][31][32][33] or laser subtractive processing methods. [15][16][17][18][19][20] A suspended hollow microchannel structure with a 3D controllable configuration can be fabricated in a way of either laser-assisted selective wet etching [21][22][23] or liquid-assisted laser ablation.…”

High‐Performance Materials for 3D Printing in Chemical Synthesis Applications

“…In addition, both are direct glass printing processes and perform the printing process at elevated temperatures requiring special expensive printing equipment. [36][37][38] Both processes allow printing fused silica glass with resolutions of a few hundred micrometers. The first indirect printing process was developed by our group using silica nanocomposites that can be cured by light and turned into transparent high-quality fused silica glass via thermal debinding and sintering.…”

“…[34,35] We have shown that these nanocomposites can be printed using benchtop stereolithography in a layer-by-layer based fashion and turned into fused silica glass during a final heat treatment (see Figure 1a). [36,37] Nanocomposites, on the other hand, have been demonstrated to have solid loadings of up to 60 vol% resulting in a linear shrinkage of only 15.66 vol%. The physical and chemical material properties of the resulting sintered fused silica glass are indistinguishable from commercial fused silica glass.…”

“…They show the same high optical transparency in the UV, visible, and infrared region, the same mechanical strength, and the same thermal and chemical resistance like commercial fused silica glass. [37] Copyright 2018, American Chemical Society. [36][37][38] Both processes allow printing fused silica glass with resolutions of a few hundred micrometers.…”

“…[33] Alternative direct glass printing processes such as direct ink writing of colloidal silica suspensions and SL printing of photocurable sol-gel precursors (mixture of a photocurable silane and tetraethylorthosilicate) have also been described (see Figure 1c,d). [36][37][38] Both processes allow printing fused silica glass with resolutions of a few hundred micrometers. Direct ink writing has even been shown for multiple glass types (SiO 2 /SiO 2 -TiO 2 ) in a single print.…”