3D printing technology encompasses many additive manufacturing techniques for the fabrication three-dimensional structures. Among the methods of 3D printing available, stereolithography (SL) has proven particularly attractive.. With high resolution and the ability to rapidly produce prototypes with complex geometries, SL provides ease of product development that is unmatched by other manufacturing methods such as injection molding, extrusion, and subtractive processes. The specific method investigated by our group is digital light processing (DLP) SL in which a pre-photopolymer resin is selectively exposed to defined projections of near-UV light and cured layer by layer to form a three dimensional object (Figure 1). Although interest in this technology has significantly increased over the past few decades, widespread implementation of this technique is limited by the narrow range of mechanical properties possessed by polymers that it can be used to print. Specifically, SL-fabricated materials tend to be either brittle with low energy-absorption capabilities, or elastic with low structural integrity. In addition to these material constraints, the layer by layer fabrication results in anisotropic effects that can create weak points within the polymer matrix. Our group aims to address these issues through investigation of chemical and physical fundamentals governing the photopolymerization printing process.   

Figure 1. Diagram displaying A) the process of digital light project (DLP) stereolithography, and B) object fabricated using DLP printing.