Multi-Material Nanoscale 3D Fabrication Based on Femtosecond Light Sheets

A major challenge in nanotechnology is to fabricate complex 3D structures with desired materials. Despite the many great efforts, the material choices are still largely limited to polymeric materials or metals. A fabrication solution for a wider class of materials without compromising the existing structural complexity, nanoscale feature sizes, and material functions remains a critical challenge. In this seminar, I will present our recent works on the parallelization of ultrafast lasers for 3D nanofabrication, achieving a record setting resolution (20 nm), laser patterning rate (300 mm³/hr), and wide material library. Specifically, an arbitrarily programmable femtosecond light sheet is generated based on the principle of spatial and temporal focusing to perform parallel material processing. We first demonstrate the use of the femtosecond light sheet to perform micro-laser machining on different materials, and next to fabricate complex 3D structures via two-photon polymerization. Lastly, by combining the femtosecond light sheets and swellable hydrogels, we further demonstrate a greatly expanded material library to include metals, metal oxides, semiconductors, dielectric materials etc. This has enabled the fabrication of nanometer-scale 3D functional devices. Our new methods provide an effective and low-cost solution to scale-up the fabrication of functional micro- and nano-structures (~$1.5/mm³). This means our technology may play a large role in fields such as healthcare, clean energy and water, computing, and telecommunications.