2014 RU RET-E in Green Energy Technology Projects
Project Title: Energy Harvesting with Inflatable Structures
Faculty Mentor: Aaron Mazzeo
Graduate Student Mentors: Jingjin Xie and Ke Yang
Project Description: We have been simulating and characterizing lift and drag on airfoils with silicone-based inflatable structures. By inflating the elastomeric regions of airfoils, we can alter their surface area and manipulate flow surrounding the entire structure.
The Mazzeo group is expanding the project to study vortex shedding on cylinders or other morphable geometries with fluid flows to create alternative forms of energy harvesting. The anticipated methods of transduction from mechanical excitation to electrical output include piezoelectric materials and linear electromagnetic generators.
A participant would get to work with graduate and undergraduate students on designing, constructing, and testing systems with embedded, inflatable structures. The construction of the inflatable structures generally involves the use of three-dimensionally printed molds to form silicone-based elastomeric bladders. We will combine these structures with harder supporting materials and integrate them with an electromechanical system. After building prototypes and coupling the structures with an electrical generator, we will run experiments in wind tunnels located on campus to characterize their performance/efficiency and the amount of power we can produce.
Project Title: Few-layer graphene synthesis using pulsed laser deposition
Faculty: Stephen Tse
Graduate Student Mentors: William Mozet
Project Description: Graphene research has surged in recent years due to its incredible properties, such as ballistic electron transport and high tensile strength to weight ratio, suggesting staggering potential applications. Efforts to produce graphene have naturally followed. Using an Nd:YAG laser of 266 nm to ablate highly ordered pyrolytic graphite (HOPG), graphene is fabricated on polished copper substrates for varying times (T = 900ºC, P = 10-5 Torr, E = 50 mJ/pulse). The graphene is examined using Raman spectroscopy with a focus on studying the number of layers grown as a function of the time of deposition using peak intensity ratios. It has been determined that the number of graphene layers decreases with decreasing deposition time while the disorderedness of the graphene crystals remain unaffected. This study advances the current state of knowledge on graphene synthesis, aiding in further efforts to not only create graphene, but also study its properties and seemingly countless potential applications.
Project Title: Developing glasses for their application in ZEBRA batteries
Faculty: Ashu Goel
Project Description: ZEBRA battery (Technical name: Na-NiCl2 battery) was invented in 1985 by the Zeolite Battery Research Africa Project (ZEBRA) group led by Dr. Johan Coetzer in South Africa. ZEBRA battery operates at ~250 oC and utilizes molten sodium aluminumchloride (NaAlCl4) as the electrolyte, molten sodium as negative electrode and nickel in discharged state and nickel chloride (NiCl2) in charged state as positive electrode. Since both NaAlCl4 and Na are liquid at the operating temperature, a sodium-conducting beta-alumina (Al2O3) ceramic is used to separate the liquid sodium from molten NaAlCl4 while alpha-Al2O3 is used as an insulating collar and a suitable glass based material is applied to join the two ceramic components. The purpose of the glass seal is to maintain a hermetic and robust sealing between alpha- and beta-Al2O3 ceramic components in the battery while being exposed to hostile alkali- and halide vapor rich environment at operating temperatures.
The primary requirements for designing a suitable glass sealant for ZEBRA batteries are as follows: minimum thermal expansion mismatch between glass and ceramic components; high thermal shock resistance; high chemical resistance towards alkali vapors and low electrical conductivity.
Researchers will explore the factors influencing battery performance.
Project Title: Percolative Dielectric Materials for Energy Storage Applications
Faculty: Kimberly Cook-Chennault
Graduate Student Mentors: Udhay Sundar and Wanlin Du
Post Doctorate Mentor: Sankha Banerjee
Project Description: Electrical energy storage plays a key role in electronics, stationary power systems, hybrid electric vehicles and pulse power applications. Traditionally, bulk ceramic dielectric oxides have been used for these applications, though they suffer from inherently low breakdown field strength, which limits the available energy per unit mass (energy density) and increases the dielectric loss.
On the other hand, polymers have high break down field strengths, low dielectric losses and can be readily processed into thin films, but suffer from relatively low dielectric permittivity, and thus low energy densities. This project focuses on development of materials that can be applied to sub-micrometer scale commercial and industrial devices such as, high density DRAM (dynamic access memory), non-volatile memory (NRAM) and capacitors. It is well known that coupling polymer and a dielectric constant material into a composite may address some of the aforementioned challenges, though the mechanisms that lead to higher dielectric constants and minimal dielectric losses are not well understood.
Researchers will fabricate and analyze composite dielectric materials with the aim of understanding the mechanisms that lead to higher dielectric constants and higher breakdown field strengths.
 Multi-Walled Carbon-Nanotube Based Flexible Piezoelectric Films with Graphene MonolayersS Banerjee, R Kappera, KA Cook-Chennault, M ChhowallaEnergy and Environment Focus 2 (3), 195-202