Position: PhD Candidate
Current Institution: Columbia University
Abstract: Role of Nanoparticle Composites in Active Devices
In recent years there has been significant work investigating potential composite materials based on electroactive polymers and nanoparticles driven by the increased commercial availability tunability and available functionalities of nanoparticles. As the demand for smaller and more flexible electronics increases multifunctional nanocomposites can unlock higher functionality and miniaturization by enabling the combination of multiple functionalities into one component. Nanocomposites with the electroactive polymer PVDF-TrFE as the host in particular are suitable for the construction of solution-processed and biocompatible devices. Composite materials can also control the polymorphic crystallization of PVDF-TrFE presenting further advantages for materials research in addition to potential device enhancements. Barium titanate (BTO) and europium barium titanate (EBTO) are promising additives for nanocomposites with PVDF-TrFE as they offer desirable material electrical and optical properties. My recently published work has shown that if a composite is developed with BTO nanoparticles less than 20 nm in diameter the PVDF-TrFE crystallinity is not significantly affected but the BTO nanoparticles do not add any additional piezoelectric or ferroelectric character despite being piezoelectric and ferroelectric themselves. This trend continues even at high concentrations due to their superparaelectric nature. This finding refutes previous work claiming increased piezoelectric and ferroelectric behavior in similar nanocomposites. EBTO contains a Eu3+ color center and shows a fluorescence with an absorption peak of 240 nm and emission at 620 nm. With absorption is in the ultraviolet range and emission is in the visible range this material can serve as sensitizer for a solar-blind UV sensor adding an interesting functionality to piezoelectric and pyroelectric devices. The electro-optical characteristics of the nanocomposite and related systems are currently being investigated with a goal of providing a template for future multifunctional nanocomposites and electro-optical devices.
Christine K. McGinn received a B.A. in Physics and B.S. in Engineering from Swarthmore College in 2016. Christine began studying at Columbia University with Prof. Ioannis Kymissis as an MS/PhD student in 2016 and obtained the MS degree in 2018. She is currently an NSF Graduate Research Fellow. Through an NSF Graduate Research Opportunities Worldwide Grant she completed research at Tampere University in Tampere Finland with Prof. Donald Lupo studying printing piezoelectric polymers in 2019. Her current research focuses on thin films for sensing applications and materials characterization of nanocomposite materials. Her research has been published in ACS Sensors Advanced Functional Materials Journal of the American Chemical Society IEEE Journal of Microelectromechanical Systems and Journal of Applied Physics. While at Columbia she served as a classroom aide for the Girls Who Code program and as president of the Columbia Graduate Society of Women Engineers chapter.