3D printing process uses tunable photochemistry

Joseph M. DeSimone, Professor of Chemistry at UNC-Chapel Hill and of Chemical Engineering at N.C. State, is currently CEO of Carbon3D. Here he co-invented the method with colleagues Alex Ermoshkin, Chief Technology Officer at Carbon 3D and Edward T. Samulski, also Professor of Chemistry at UNC. Currently on sabbatical from the University, DeSimone has focused on bringing the technology to market, while also creating new opportunities for graduate students to use the technique for research in materials science and drug delivery at UNC and NCSU.

CLIP, which stands for Continuous Liquid Interface Production, manipulates light and oxygen to fuse objects in liquid media, making it the first 3D printing process that uses tunable photochemistry instead of the layer-by-layer approach that has defined the technology for decades. The technology works by projecting beams of light through an oxygen-permeable window into a liquid resin. Working in tandem, light and oxygen control the solidification of the resin, creating commercially viable objects that can have feature sizes below 20µm, or less than one-quarter of the width of a piece of paper.

Through a sponsored research agreement between UNC-Chapel Hill and Carbon 3D, the team is currently pursuing advances to the technology, as well as new materials that are compatible with it. CLIP enables a very wide range of material to be used to make 3D parts with novel properties, including elastomers, silicones, nylon-like materials, ceramics and biodegradable materials. The technique itself provides a blueprint for synthesising novel materials that can further research in materials science.

Rima Janusziewicz and Ashley R. Johnson, graduate students in DeSimone’s academic lab, are co-authors on the paper and are working on novel applications in drug delivery and other areas.

“By rethinking the whole approach to 3D printing, and the chemistry and physics behind the process, we have developed a technology that can create parts radically faster than traditional technologies by essentially ‘growing’ them in a pool of liquid,” said DeSimone.

“In addition to using new materials, CLIP can allow us to make stronger objects with unique geometries that other techniques cannot achieve, such as cardiac stents personally tailored to meet the needs of a specific patient,” commented DeSimone. “Since CLIP facilitates 3D polymeric object fabrication in a matter of minutes instead of hours or days, it would not be impossible within coming years to enable personalised coronary stents, dental implants or prosthetics to be 3D printed on-demand in a medical setting.”

CLIP’s debut coincides with the United Nation designating 2015 as the International Year of Light and Light-Based Technlogies, which recognises important anniversaries of scientific advances enabled with light.