Research

Laser Engineering Methods for New Functional Materials

  • Tunable Terahertz Bandpass Ultrathin Metamaterials

Terahertz (THz) imaging/sensing has attracted much attention within the past decade as an emerging nondestructive evaluation technique.

Our group has recently developed a new Laser-based Metamaterial Fabrication (LMF) process for terahertz bandpass metasurfaces on dielectric substrates such as glass, quartz and polymers. This new method firstly deposits an ultra-thin metal film on dielectric optical lens materials, and then laser patterns the surface film to achieve the bandpass filtering effect in the THz spectra. In comparison with the existing micro-/nano-fabrication techniques of THz devices/filters, the LMF process involves a much simpler fabrication process, ease of scaling up, and lower manufacturing cost.

More importantly, our research presented a new electronically tunable THz bandpass optics which is also highly transparent in the visual spectrum. Our results render an economical technique capable of treating large surface area for multi-functional metamaterials and provide a viable solution for fabrication of tunable THz lens for sensing and imaging.

More details can be found in the Scientific Reports paper.  

  • Fast Surface Nanostructuring of Metal Alloys for Tunable Wettability

Our research in this area aims to develop an inexpensive high-throughput laser-silanization based process to fabricate micro/nanoscale structures on the metal surface to achieve multi-functionalities that combines tunable wettability, self-cleaning, antibacterial, anti-reflectivity and anti-icing. The existing technologies take a while (up to two full hours to treat a single square inch of metal) whereas this technology few tens of seconds to process the same. The main objective of our research is to understand the processing science of surface micro/nanostructure generation on the engineering metal alloys. 

We developed fundamental scientific hypotheses for the new nanosecond laser-based high-throughput surface nanostructuring (nHSN) process that efficiently treats large-surface-area engineered metal alloys, and experimentally proved them that contribute to the generation of the surface micro/nanostructure and favorable chemistry to achieve tunable wettability.

Our results showed that surface chemistry of the micro/nanostructured surface is also equally critical to achieving target wettability condition. Similar micro/nanostructured surface with fluro-silane chemistry behaved as water repellent whereas with cyano-silane chemistry behaved as water attractive. The final performance of the nanostructured metal surface is a complex combination of surface micro/nanostructures and surface chemistry. This is the biggest take away from this research which has never been reported before.

YouTube Video 

 

Materials Processing

 

Physics-based Modeling of Processes and Materials 

 

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