Julius Edgar Lilienfeld Prize Talk: Plasmonics: Photonic Nanoscience with Societal Impact

Metallic nanoparticles, used since antiquity to impart intense, vibrant color into materials, then brought to scientific attention in the 19^th century as “Faraday’s colloid”, have more recently become a central tool in the nanoscale manipulation of light. As one begins to assemble metallic nanoparticles into useful building blocks, a striking parallel between the plasmons- the collective electronic oscillations- of these structures and wave functions of simple quantum systems is universally observed. While our scientific foundation for the field of Plasmonics has been built on nanoparticles consisting of noble and coinage metals, more recently we have begun to question whether the same, or similar, plasmonic properties can also be realized in more sustainable materials. Aluminum, the most abundant metal on our planet, can support high-quality plasmonic properties spanning the UV-to-IR region of the spectrum. Nanoscale graphene, when reduced to the molecular limit, sustains many plasmonic properties but introduces new ones such as single-electron color switching, which can be utilized in unique electrochromic devices. We have previously introduced photothermal effects for biomedical therapeutics; now, years after their initial demonstration, this approach is being utilized in human trials for the precise and highly localized ablation of cancerous regions of the prostate, eliminating the highly deleterious side effects characteristic of conventional prostate cancer therapies. Photothermal effects can also be harvested for sustainability applications, which we have most recently demonstrated in an off-grid solar thermal desalination system that transforms membrane distillation into a scalable water purification process.