LLNL unlocks the secrets of nanoscale 3D printing

LLNL researchers can print woodpile lattices with submicron features a fraction of the width of a human hair. Image by Jacob Long and Adam Connell/LLNL.

Lawrence Livermore National Laboratory (LLNL) researchers have discovered novel ways to extend the capabilities of two-photon lithography (TPL), a high-resolution 3D printing technique capable of producing nanoscale features smaller than one-hundredth the width of a human hair.

The findings also unleashes the potential for X-ray computed tomography (CT) to analyze stress or defects noninvasively in embedded 3D-printed medical devices or implants.

LLNL researchers describe cracking the code on resist materials optimized for two-photon lithography and forming 3D microstructures with features less than 150 nm. Furthermore, researchers were able to tune and increase the amount of X-rays the photopolymer resists could absorb, improving attenuation by more than 10 times over the photoresists commonly used for the technique.

By tuning the material’s X-ray absorption, researchers can now use X-ray-computed tomography as a diagnostic tool to image the inside of parts without cutting them open or to investigate 3D-printed objects embedded inside the body, such as stents, joint replacements or bone scaffolds. These techniques also could be used to produce and probe the internal structure of targets for the National Ignition Facility, as well as optical and mechanical metamaterials and 3D-printed electrochemical batteries.