SUMMARY

Nanoscale metallic structures are highly valuable due to their distinctive scale-dependent properties, but their fabrication remains challenging. Current nanoscale fabrication techniques can only produce small volumes or require expensive foundry-based microfabrication facilities. These limitations hinder practical adoption of nano-enabled devices. Light-based direct writing techniques are an attractive set of processes due to their ability to print arbitrary structures from digital images, thereby eliminating the need for expensive physical masks. However, these processes are still limited by the cost versus resolution tradeoff. For example, digital light projection is an inexpensive technique but it cannot produce metallic features smaller than 5 μm, whereas multiphoton techniques can produce sub-diffraction nanoscale features but require expensive femtosecond lasers. In this work, we propose to overcome this tradeoff by creating a sub-diffraction metal printing technique using low-intensity light. We will achieve this by leveraging the spatiotemporal coherence properties of superluminescent light to realize high edge contrasts during light projection and by implementing a projection-based photoreduction metal printing technique. Our work will generate the processing science for the cost-effective fabrication of nanoscale metallic structures using low-intensity light-based direct writing techniques. Specifically, we will: (i) identify the process conditions that generate sub-diffraction nanoscale printing, (ii) quantify the rate limits, and (iii) generate physics-based models to predict the morphology of the printed nanostructures that are formed via nucleation and growth of nanoparticles. This work will result in a scalable nanomanufacturing capability for applications such as printed electronics, photonics, and sensing.