Pixel patterns harness diffraction for faster, more accurate nanoscale 3D printing

Researchers at the Georgia Tech School of Mechanical Engineering have unveiled a groundbreaking technique for nanoscale 3D printing that significantly boosts both speed and precision. Led by Sourabh Saha, associate professor and Woodruff Faculty Fellow, the team's work, conducted by doctoral student Harnjoo Kim, is detailed in a paper published in Nature Communications.

Nanoscale 3D printing enables the creation of structures far smaller than the width of a human hair, with potential applications in advanced computing, optics, biomedical devices, and clean energy technologies. However, a major hurdle has been balancing printing speed with accuracy. Traditional methods can produce highly precise structures but are too slow for practical manufacturing, while high-speed approaches often sacrifice accuracy due to the difficulty of controlling light dosage across different areas of a structure.

Saha's group previously developed a method to dramatically increase printing speed by processing entire planes of material simultaneously. However, maintaining precise control over light delivery to different regions of a structure remained a challenge. To address this, Saha and Kim devised a motif-based approach, constructing intricate light patterns from a series of small, carefully designed elements, akin to creating a painting with deliberate brushstrokes rather than a single wild splash.

Their technique leverages a binary pixel device—capable of only turning pixels on or off—to generate multiple light intensity levels. By arranging these pixels into precise patterns, the researchers cleverly exploit the phenomenon of diffraction, typically viewed as a limitation, to their advantage. By designing patterns smaller than the diffraction limit, they achieved precise control over light intensity across the printing area while maintaining a consistent spot size, resulting in faster and more accurate prints.

The breakthrough allows for up to 100 times faster printing speeds with finer control over printed features. This advancement could revolutionize various industries, from micro-optical components for imaging and communications to biomedical devices, microelectromechanical systems, and fuel capsules for fusion energy. Saha's team is now working on commercializing the technology, aiming to make nanoscale additive manufacturing more affordable and accessible for real-world applications.