SEED Grants 2014
Nanostructured surfaces for electrokinetick energy conversion; toward capillary-driven energy storage
Carlos Colosqui
Mechanical Engineering, SBU
Antonio Checco
Condensed Matter Physics and Materials Science, BNL
Solid surfaces in contact with a liquid-electrolyte solution can develop significant charges which, in turn, induce a layer of counterions in the adjacent liquid. The described interfacial configuration is known as the electric double layer (EDL). Fluid flow–caused by pressure gradients and/or other forces–transports the mobile counterions in the EDL giving rise to a net electric current. This electrokinetic phenomenon enables the conversion of mechanical and other forms of energy (e.g., capillary energy) into electrical energy. Intrinsic conversion efficiencies are hindered by the small thickness of EDL (1-100 nm) and large hydrodynamic shear at the liquid-solid interface. Nanostructured surfaces can significantly enhance conversion efficiencies by thickening the mobile counterion layer and promoting hydrodynamic slip.
This project integrates theoretical and computational modeling with nanofabrication and characterization techniques in order to engineer nanostructured surfaces for enhanced electrokinetic energy conversion. The PI (Colosqui) will model wetting and electrokinetic phenomena at nanostructured surfaces using molecular dynamics simulations and system- level analysis. The Co-PI (Checco) will fabricate and characterize suitable nanostructured surfaces using state-of the-art nanofabrication and characterization techniques. Computational and experimental facilities required for this project are available at Brookhaven National Laboratory. The designed nanostructured surfaces will be integrated into basic microfluidic devices consisting of a single nanochannel with dimensions numerically optimized for maximal energy conversion. Electrokinetic energy conversion efficiencies of the prototype devices will be experimentally measured for pressure-driven and capillary-driven/assisted flows.
Graphene-based Terahertz/Infrared Camera
Xu Du
Department of Physics & Astronomy, SBU
Dmitri Kharzeev
Department of Physics & Astronomy, SBU
Mingzhao Liu
Center for Functional Nanomaterials, BNL
Professors Xu Du and Mingzhao Liu propose to establish a joint Stony Brook/BNL research effort to develop graphene-based plasmonic devices that are uniquely suited for the generation and detection of electromagnetic radiation in the Terahertz (THz)/Infrared (IR) range. We will use a suspended graphene nano/micro-ribbon-array under Joule heating as a source of THz/ IR radiation. We will also design, fabricate and characterize a graphene nano/micro ribbon plasmonic sensor that will detect the photocurrent induced by the THz/IR radiation. Combining the two devices, we will demonstrate a fast, sensitive, and compact graphene-based THz single-pixel camera, for THz/IR imaging. The proposed THz Camera would have extensive applications, especially in biomedical imaging.
Molecular Structure of Thin-film Amorphous Selenium
Amirhossein Goldan
Department of Radiology, SBU
Eric Stach
Electron Microscopy, CFN, BNL
Amorphous selenium (a-Se), in the form of thermally deposited thin film, is the only x-ray photoconductor that has been successfully developed for making large area medical image sensors. It is also the only amorphous material with avalanche multiplication gain that has been utilized in ultra-sensitive optical cameras. The low-cost and high image quality provided by a-Se prompted intensive investigation of its application in photonics and medical imaging, and our group at Stony Brook University (SBU) is among the leaders in this field.
The operation and reliability of a-Se sensors rely on the stability of the molecular structure, and its ability to hinder recrystallization. However neither the molecular structure of a-Se thin films nor the conditions for recrystallization have been established. Previous studies of the structural species of a-Se are clouded with much uncertainty and somewhat contradictory results regarding the dominance of polymeric chains versus monomer rings. Analysis of the diffraction radial distribution functions are inconclusive because of the similarities between the crystalline allotropes of selenium in terms of the coordination number, bond length, bond angle, and dihedral angle.
In this research, we take a much different approach to probe the molecular symmetry of the thermodynamically unstable amorphous/glassy phase. We combine (1) the glass thermal analysis (via differential scanning calorimetry) and (2) electron microscopy of crystals transformed from the frozen glassy phase. We verify the structure of the transformed metastable and stable crystalline structures using transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). The proposed SBU-BNL collaboration provides a unique opportunity to seek answers to these important questions, and fuel future development of novel sensor structures. It will also form the foundation for future investigation of the nature of glass, glass transition, and phase transformation.
Low-Carbon Energy (LCE) Initiative
Devinder Mahajan
Materials Science & Engineering, SBU
Mante Ofei
Sustainable Energy Technologies, BNL
This proposal is a continuation of the L-CEM initiative that was started in 2013 to build upon the progress made last year and then follow-up on the ongoing work. The goal is have funding in-place from multiple sources by next year that will build a solid funding base for low-carbon energy process research at SBU and BNL. The proposal aligns with the current SBU-BNL initiatives in Energy, specifically on Energy Production.
The Low-Carbon Energy Initiative
The UN-sponsored 2007 IPCC report (1) provided impetus to address the increasing atmospheric CO2 levels, though much controversy remains in the implementation, both within the scientific community and in the global political arena. The International Energy Agency (IEA) “World Energy Outlook” report that the share of global fossil-based primary energy supply will still account for 74% in 2035 necessitates that any carbon management scheme must include both fossil fuels and renewables. We propose the initiative: “Low-Carbon Energy” (LCE) that is based on a sensible approach to carbon management. The LCE initiative is timely in that Stony Brook University is assessing two major energy initiatives: 1) Expansion of energy effort at Turkana Basin Institute (TBI) in Kenya and 2) Production of next-generation liquid fuels, locally on Long Island, from renewable biogas source at landfills.
The Advanced Energy Research & Technology Center (AERTC) at Stony Brook University, New York, is a $45 million R&D facility funded by the State of New York. The mission of the premier center is ENERGY research. The key research thrust areas in AERTC are: 1) Smart Grid, 2) Energy Storage, 3) Bioenergy, 4) Mechanical Energy Harvesting and 5) Energy policy. More information about AERTC is available at www.aertc.org. Central to the Bioenergy energy effort at AERTC is the Center for Bioenergy Research & Development (CBERD), a multi- university effort funded by the National Science Foundation (NSF) under the Industry/University Cooperative Research Centers (I/UCRC) program. The Stony Brook University site of CBERD is housed in two new laboratories in the AERTC building together with the L-CEM initiative. The focus is on economical biomass processing to fuels in skid-mounted units. More information on CBERD can be found at: www.bioenergynow.org.