3D Print and Shrink Microfabrication of Polymer-derived Ceramics: Silicon oxycarbide Glass-Ceramic Microneedles and Microfluidics

Polymer-derived ceramics are advancing various sectors, such as health, defence, and aerospace, however, their manufacturing has been cumbersome, unsafe, and design-limited. Some efforts have been made to 3D print polymer-derived ceramics, however, the physio-chemical properties of those pre-ceramic resins have prevented their use in microfabrication and generating glass-ceramic phases. Here, a new pre-ceramic resin and microfabrication method, 3D print and shrink, has been developed to enable the fabrication of high-resolution glass-ceramic components. The resin utilises a binary thiol-acrylate based photocurable system, which has been optimised for high-resolution 3D printing and high isotropic shrinkage during pyrolysis, without incurring cracks or defects even at higher temperatures, as required for generating silicon oxycarbide glass-ceramics. The resin has also been found to overcome the limitations of oxygen inhibition and short shelf-life associated with their current acrylate and thiol-ene counterparts, respectively. The method has been validated for fabricating both positive and negative micro-features. A single-pixel resolution (ca. 30 um) has been maintained throughout the printing process, which has been further improved to a half-pixel resolution (ca. 15 um) in the sintered glass-ceramic, allowing 3D printing of a microneedle patch with ca. 28 um tips and a microfluidic distributor with ca. 250 um ID channels.