New Two-Photon Polymerization Technique Revolutionizes 3D Printing

A groundbreaking two-photon polymerization technique developed by Purdue University researchers paves the way for more accessible and cost-effective high-resolution 3D printing, with potential applications spanning electronics, biomedical micro-robots and tissue engineering scaffolds.

Researchers at Purdue University have unveiled a pioneering two-photon polymerization technique that promises to revolutionize the cost-efficiency and accessibility of high-resolution 3D printing.

The method leverages a novel combination of a relatively low-cost laser emitting nanosecond pulses and a reduced-power femtosecond laser. This advancement could democratize the use of high-resolution 3D printing in diverse fields, including electronics, biomedical devices and tissue engineering.

“We combined a relatively low-cost laser emitting visible light with a femtosecond laser emitting infrared pulses to reduce the power requirement of the femtosecond laser,” Xianfan Xu, the study’s team leader and James J. and Carol L. Shuttleworth Professor of Mechanical Engineering at Purdue, said in a news release. “In this way, with a given femtosecond laser power, the printing throughput can be increased, leading to a lower cost for printing individual parts.”

Traditionally, two-photon polymerization relies on expensive femtosecond lasers to delicately craft intricate microstructures. While effective, the high cost of these lasers has limited the widespread adoption of the technique in manufacturing processes.

The team’s new approach, however, could change that paradigm by significantly reducing laser power requirements — up to 50%, according to findings published in the Optica Publishing Group journal, Optics Express.

“3D printing with high resolution has many applications, including 3D electronics devices, micro-robots for the biomedical field and 3D structures or scaffolds for tissue engineering,” added Xu. “Our novel, 3D printing approach can be readily implemented in many existing femtosecond laser 3D printing systems.”

The research team aimed to increase printing speed while reducing costs, focusing on the precise photochemical processes involved in two-photon polymerization. In conventional processes, the femtosecond laser initiates a crucial photochemical reaction that precedes the actual printing. Xu and his team innovatively used a more affordable 532 nm nanosecond laser for this step, thereby decreasing the femtosecond laser’s workload.

This technique involved a delicate balancing act between printing and inhibition caused by the two lasers. The researchers developed a mathematical model to dissect these photochemical processes, identifying the optimal interaction between the single-photon excitation from the nanosecond laser and the two-photon excitation from the femtosecond laser.