Fast DLP 3D Printing Gets Microscale Breakthrough

In an era where the minutiae of technology often determine the leap towards innovation, researchers at Stanford University have made a significant breakthrough with microscopic manufacturing. Spearheaded by Jason Kronenfeld, a PhD candidate, and under the guidance of Carbon founder Joseph DeSimone, the Sanjiv Sam Gambhir Professor in Translational Medicine, the team has developed a novel 3D printing technique that promises to revolutionize industries from pharmaceuticals to microelectronics.

Dubbed roll-to-roll continuous liquid interface production (r2rCLIP), this new method improves the efficiency of producing microscale particles – so small they resemble specks of dust to the naked eye. These particles have wide-ranging applications, including drug and vaccine delivery, microfluidics, and even as abrasives for intricate manufacturing processes.

The Technical Leap: From CLIP to r2rCLIP

The journey to r2rCLIP began with DeSimone’s development of continuous liquid interface production (CLIP) circa 2015. By relying on an oxygen-permeable window, DeSimone’s startup, Carbon, kicked off the continuous digital light processing (DLP) revolution that we now see driving the DLP space. Building on this, r2rCLIP enhances scalability and speed, enabling the production of up to one million customizable microscale particles a day.

The r2rCLIP setup in the DeSimone lab runs from right to left. The printing occurs at the area below the red piece. (Image credit: DeSimone Research Group)

This new technique mirrors the efficiency of an assembly line, marking a shift from labor-intensive manual processes to automated production. The r2rCLIP method involves tensioning a film, onto which hundreds of particle shapes are simultaneously printed. This film then proceeds through various processes – washing, curing, and shape removal – before being rolled up again, ready for another cycle.

Implications and Applications

The implications of r2rCLIP are significant. Kronenfeld and DeSimone highlight the balance they’ve struck between speed and resolution, which is critical for applications that require large volumes of high-precision parts.

“We’re navigating a precise balance between speed and resolution,” said Kronenfeld. “Our approach is distinctively capable of producing high-resolution outputs while preserving the fabrication pace required to meet the particle production volumes that experts consider essential for various applications. Techniques with potential for translational impact must be feasibly adaptable from the research lab scale to that of industrial production.”

While 3D printing has already made waves in producing macroscopic objects, such as dental implants or athletic equipment, r2rCLIP opens new doors for microscale manufacturing. The researchers have already begun experimenting with particles made from ceramics for microelectronics, and hydrogels for drug delivery. These materials, and the intricate shapes r2rCLIP can produce, could lead to breakthroughs in several fields.

The current state of DeSimone’s former company is unknown. Carbon did not attend the Additive Manufacturing Users Group conference this year, perhaps opting for non-AM-specific events for its marketing budget. Meanwhile, numerous continuous DLP companies have emerged on the scene, including some from China that make very low-cost equipment.

While Carbon has been successful in some key applications, including for footwear and helmets, it’s difficult to tell just how far these use cases have gotten the company. The once-unicorn may be feeling the pressure of that valuation from investors during the current macroeconomic environment. What could ensure success for the firm could be a new technology and lucrative killer app.

Supposing that Carbon were able to commercialize r2rCLIP, a possibility raised by the very naming of this technology after DeSimone’s original invention, it could push the firm into the medical and electronics spaces. DeSimone has been involved in a unique application of continuous DLP for the 3D printing of microneedle patches, meant to be more effective delivery mechanisms for vaccines. Additionally, Boston Micro Fabrication, Fabric8Labs, and others have demonstrated how valuable the ability to 3D print tiny electronics parts could be. Of the methods for 3D printing that have been described as most promising for electronics manufacturing is roll-to-roll. Expanding from the macro to the micro may be exactly what Carbon needs to continue moving forward.