CAREER: Adaptive Photonic Polymers

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

PART 1: NON-TECHNICAL SUMMARY Unlike electronic devices that control information by affecting the flow of electrons, photonic devices control information by affecting the flow of photons or light and have the potential to overcome the speed and bandwidth of electronic devices. Key to photonic devices is their basic components -- photonic crystals, which are periodic nanostructures consisting of regularly repeating regions of high and low dielectric constants. Transmission of light through such a crystal is prevented due to multiple reflections at the interfaces between alternating dielectric domains; this occurs when the wavelength is comparable to characteristic domain sizes. The band gaps of most existing photonic crystals, however, cannot be actively controlled because once a nanostructure is formed, its domain size cannot be changed. It remains a challenge in the development of adaptive photonic crystals to control light on-demand. This project aims to establish the foundational knowledge required to design and create Adaptive Photonic Polymers -- polymeric photonic crystals that enable active control of visible and infrared light. Educationally, in addition to providing research opportunities for graduate students, undergraduates, and high school students from diverse backgrounds, the topics considered in this program will be integrated into a newly developed course, "Advanced Polymers." The project also incorporates a number of outreach activities. PART 2: TECHNICAL SUMMARY This research program aims to establish the molecule-microstructure-property-function relation for Adaptive Photonic Polymers -- polymeric photonic crystals that enable on-demand control of light. The central hypothesis is that exploiting the self-assembly of architecturally designed block copolymers enables responsive periodic dielectric nanostructures with exceptionally large characteristic lengths necessary for manipulating light of a wide range of wavelengths. The PI's work will focus on: (i) development of methods for controlled synthesis of block copolymers with extreme molecular architecture such as large diameter and high molecular weight; (ii) determining the molecular architecture for which the polymers form long-range, ordered nanostructures of large characteristic lengths necessary for visible and infrared light; (iii) establishing the causal relation between microstructure and macroscopic optical properties; (iv) quantifying the response of optical properties to external stimuli using custom-developed in-situ characterization techniques. The experimental studies will be corroborated by scaling theory and self-consistent field theoretical simulations. Using the fundamental understanding gained and the technologies developed through these studies, active fast control of visible and infrared light will be demonstrated using one Adaptive Photonic Polymer. This research will be integrated into a variety of educational experiences in the laboratory and the classroom at the graduate, undergraduate, and 6-12 levels. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.