(351c) Single-Digit Micron CLIP 3D Printing, Modeling and Applications

The current landscape of high-resolution 3D printing technologies typically involves a tradeoff between scalability and resolution. Existing technologies have achieved nanometer scale print precision but suffer from much lower print speed, making the technology not easily scalable. Here, we present a novel 3D printing technology that combines micro-DLP with Continuous Liquid Interface Production (CLIP) technology that can print at single-digit micron scale resolution with a print speed up to 200 times greater than other existing high-resolution printing technologies.

The design and printing strategy of the single-digit micron CLIP printer involves several sub-components. To achieve single-digit micron resolution, we have designed and implemented a home-built projection optics system, an in-line camera system to monitor the projection pattern and a stand-alone contrast-based focusing algorithm to achieve an optimal projection plane. To optimize and provide a full understanding of the high-resolution CLIP 3D printing process, we have developed a physical model that involves Zemax based optics point spread function prediction, reaction kinetics and momentum transport model using lubrication theory that provides insights into the photopolymerization gradient, flow velocity profile and mass transport in the CLIP system for both Newtonian and non-Newtonian polymeric materials. It is observed both experimentally and from modeling that a delicate control of UV projection intensity, printing step size, and waiting time between exposures are critical to achieving the desired resolution. Finally, a physical model informed software-controlled printing strategy is adopted. The step-and-expose printing process allows us to resolve single-digit micron prints with high-precision.

The high-resolution CLIP platform has shown its potential to print with various materials (including hydrogels and elastomeric materials), with applications ranging from drug delivery and continuous health monitoring platforms to microfluidic device fabrication, force sensors and electronic packaging devices. We envision this new technology can be transformative in providing researchers across many domains with improved access and freedom to form and create designs.