Speaker: Akshit Peer, ECpE Graduate Student
Advisor: Rana Biswas
Title: Nanopatterned Surfaces for Applications in Plasmonic Optoelectronics and Biomedical Systems
Abstract: Periodically patterned nanostructures have imparted profound impact on diverse scientific disciplines. In physics, chemistry, and materials science, artificially engineered photonic crystals have demonstrated unprecedented ability to control the propagation of light through strong diffractive effects. The field of photonic crystals has led to many technical advances in synthesizing periodically patterned surfaces in dielectric materials and optoelectronic devices such as solar cells and light emitting diodes. In the field of biomaterials, it is of great interest to explore how such periodically patterned structures control diverse biological functions by varying the available surface area – a key attribute for cell growth, surface hydrophobicity, and drug delivery. We describe two closely related scientific applications of periodically patterned nanoscale structures. In the first project, we experimentally design a large-area plasmonic metasurface by coating thin gold layer on a sub-750nm periodic nanocup array fabricated on polystyrene using soft lithography. The optical metasurface shows extraordinary optical transmission at a wavelength close to the structure period. The resonance wavelength for transmission can be tuned by changing the period of the structure, which opens up new avenues in subwavelength optics for designing optoelectronic devices and biological sensors. The second area deals with the nanoscale patterned biopolymers as templates for controlling the release of drugs coated on the surface. From the eight-day drug release experiment, we find that nanopatterned polymers release the drug slower as compared to the flat polymer surfaces. The slow-down in the drug release from nanopatterned surfaces is attributed to increase in the surface hydrophobicity confirmed by the contact angle measurements and microfluidic simulations. This nanoscale drug release control scheme will be of importance to future drug-eluting stents in cardiac therapies.