|
Conventional optical sensing devices require bulky and sophisticated optical systems to obtain high-quality information. Over the last decades, photonic metamaterials have attracted considerable interest in various sensing applications due to their compactness and high performance capabilities. However, millions of years of evolution in the biological world has developed a plethora of unique micro- and nanoscopic photonic structures to perform versatile vision and sensory functions.
In this talk, I will discuss how the development of nanophotonic devices harnessing bioinspired attributes can provide novel yet highly practical solutions for ophthalmic sensing applications. Inspired by the multifunctional nanostructures on the wings of glasswing butterflies, we first develop Si3N4-based nanostructures onto a Fabry-Perot-resonator-based intraocular pressure (IOP) sensor for glaucoma management. The metasurface integration onto the IOP sensor led to a 2.5-fold improvement in readout angle allowing easy handheld monitoring and in a one-month in vivo study conducted in rabbits, showed a 3-fold reduction in IOP error and 12-fold reduction in tissue encapsulation and inflammation, compared to an IOP sensor without nanostructures.
I will further show its application in optical wearables and contact lenses where, we developed a nanostructured scleral lens with enhanced optical, bactericidal, and sensing capabilities. The bioinspired nanostructures, made on biocompatible parylene thin-films are mounted on the anterior and posterior side of a traditional scleral lens. Compared to a traditional scleral lens, the nanostructured scleral lens minimizes glare at large viewing angles of 80o by 4.3-fold, and block UVA light while offering greater transmission in the visible regime. Furthermore, they display potent bactericidal activity against Escherichia coli, killing 89% of tested bacteria within 4 hr in vitro. The same nanostructures conformally coated with gold are used to perform simple, rapid, and label-free multiplex detection of lysozyme and lactoferrin (protein biomarkers of chronic dry eye disease) in artificial and whole human tears using drop coating deposition Raman spectroscopy within their physiological and pathological concentration range.
|
