New high-speed microscale 3D printing technique

Researchers at Stanford University have developed a new process for 3D printing microscopically small particles. The so-called r2rCLIP technology (roll-to-roll continuous liquid interface production) enables the production of up to one million customized microparticles per day.

The tiny particles have a wide range of applications, for example in drug and active ingredient release, microelectronics, microfluidic systems or as abrasives in precision mechanics. However, the precise coordination of light projection, movement and material properties has so far posed a challenge for scalable production.

“With r2rCLIP, we can now produce much more complex shapes on a microscopic scale and from a variety of materials – at a speed previously unattainable for particle production,” explained Jason Kronenfeld from the DeSimone lab, lead author of the study published in Nature.

The new method is based on the CLIP (Continuous Liquid Interface Production) process, in which UV light is projected to cure liquid resin layer by layer. An oxygen-permeable intermediate layer prevents the material from adhering to the light source.

In the r2rCLIP process, a long resin film is passed through various stations: Printing, washing, curing and removal of the particles. At the end, the empty film is rolled up again, similar to a production line. Automation enables mass production, whereas previous approaches required time-consuming manual post-processing.

“We are walking a fine line between speed and resolution. Our approach combines high detail sharpness and the production rates required for many applications,” says Kronenfeld. The researchers are already experimenting with hard ceramic and soft hydrogel particles for areas such as microelectronics or controlled drug release.

Details of the research are published in the specialist article “Roll-to-roll, high-resolution 3D printing of shape-specific particles”.