bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photopolymerization and Metalization for Fabricating Functional Devices and Metamaterials
Authors: Kawata Satoshi , Tanaka Takuo , Takeyasu Nobuyuki , Nakanishi Sana 
Published: April 2011

AbstractWe present three-dimensional micro/nano-fabrication techniques to create new photonic and functional devices. We have demonstrated two-photon-induced photopolymerization for fabricating 3D micro/nano-structures [1, 2]. In this method, arbitrary three-dimensional polymer structures are fabricated by scanning tightly focused infrared femto-second laser in three dimensions. Recently, we extended this technique to fabricate functional micro devices including photonic band-gap crystals [3] and movable micro-springs. The shrinkage of polymer during polymerization is utilized to reduce the structure size beyond the diffraction limit of light [4]. A micro-lens array with 2500 lenses is used to produce a mass of structures in parallel. By using this micro-lens array system, we fabricated 800 micro-springs and micro-cubic structures by single laser scanning [5]. In this presentation, metalization of fabricated polymer structures will also be described. We coat metal on the surface of polymer by electroless metal plating, but not on the glass substrate [6]. Hydrophobic coating was pre-made on the glass substrates and polymer surface is modified with Sn2+-ions. With this method micro-coil array is metalized [7]. Micro-coil array exhibits negative refraction due to the excitation of magnetic field through coils. We would like to show our design of the structure [8]. In the end, we talk about our newly invented diffraction-free imaging with nano metal rod array [9].
Fabrication of Polymeric Composite Nanostructures Containing Ferritin Nanoparticles and Carbon Nanotubes
Authors: Shin Min Kyoon , Park Sang Jun , Yoon Seong Gil , Lee Chang Kee , Shin Kwang Min , Shin Su Ryon , Gu Bon Kang , Kim Min Sup , Kim Yu Jin , Kim Seon Jeong 
Published: April 2011

AbstractComposite nanofibers including ferritin nanoparticles or multiwalled carbon nanotubes (MWCNTs) were fabricated to enhance the physical properties of the nanofibers, such as the elastic modulus and electrical conductivity. The ferritin was homogeneously incorporated in the polymeric nanofibers, but excess carbon nanotubes (CNTs) added to the polymer solution resulted in the fabrication of composite nanofibers with rough surfaces. PVA/ferritin/CNT composite nanofibers were fabricated that had smooth surfaces, and had a good dispersion of ferritin and CNTs. These composite nanofibers are applicable to artificial muscles requiring enhanced physical properties.
Effects of the Ultra Low Diluted Ceria-Based Slurry on the Planarization Characteristics of Multi-Layer Exposed Surfaces
Authors: Hwang Kyung Ho , Choi Jae Gon , Lee Myung Shin , Choi Yong Soo , Choi Geun Min , Song Yong Wook 
Published: April 2011

AbstractPlanarization characteristics of ultra low diluted Ceria (CeO2) based slurry, especially a multi-layered Chemical Mechanical Polishing (CMP) process, have been studied. The multi-layer represents the polished film consists of more than two different materials, so that, more than two different materials are exposed to the polished surface. In this work, ultra low diluted ceria based slurry was introduced to minimize micro-dishing effect of the process such as a storage node contact and a bit line contact in 80nm feature sized DRAM device, which has multi-layer film surfaces. As a result, we can minimize micro dishing of silicon dioxide and polycrystalline silicon at memory cell area, and silicon dioxide dishing at peripheral area.
Rapid Synthesis of Dielectric Films by Microwave Assisted CVD
Authors: Ndiege Nicholas , Subramanian Vaidyanathan , Shannon Mark , Masel Rich 
Published: April 2011

ABSTRACTFilm deposition methods have been the focus of renewed interest in the past decade due to calls for cheaper and more environment friendly deposition techniques as well as better quality of films. This paper describes a novel deposition technique: Microwave assisted chemical vapor deposition (MACVD). This technique utilizes inexpensive equipment and works at temperatures close to room temperature and ambient pressures. Deposition rates are very high (>1 micron a minute) and the resulting films are of high quality i.e. high density, stability. Conventional deposition techniques such as epitaxy, e-beam evaporation and LPCVD can achieve high quality films but the financial and environmental costs are high. This study considers the MACVD of a high k dielectric film (Ta2O5) on silicon for dielectric and insulation applications. Films generated are dense and stable with thicknesses varying from 60 nm to 62 microns. Depth profile studies of 575nm thick MACVD derived films show results similar to that of high quality films generated via MOCVD. Characterization of the resulting films was done using XRD, SEM, XPS, AES and profilometry techniques.
Stack of BioCells Converting ATP to Electrical Power and Possible Applications
Authors: Sundaresan Vishnu Baba , Sarles Stephen Andrew , Leo Donald J. 
Published: April 2011

ABSTRACTPlant and animals convert absorbed nutrients into the most readily available form of biochemical energy in cells - Adenosine triphosphate (ATP). Ion transporter proteins in the cell membranes hydrolyze ATP and use the energy from the reaction for ion transport across cell membranes. The BioCell is an energy conversion device inspired by ion transport through cell membranes that uses a proton-sucrose cotransporter (SUT4) to convert the chemical energy in ATP into electrical energy. Experiments on a single cell demonstrated that the BioCell behaves like a constant current power source with 10 - 22 kΩ internal resistance. The single cell developed a peak power of 0.7 μW per cm2 of bilayer lipid membrane (BLM) area reconstituted with 1 mg of SUT4 and 1 μl of ATP-ase at 10 kΩ load in the external circuit. The actual peak power output from the cell was 160 nW for a BLM area of 0.079 cm2 carrying 0.2 mg of SUT4 and 15 μl of ATP-ase. The 160 nW of electrical power that could be sourced from the cell with a 10 kΩ load (41 mV and 4 μA) is not sufficient to run a low power electronic device and needs to be scaled up to few microwatts. This article discusses our experimental results from stacking a BioCell in series and parallel to develop higher stack voltage and current. We observe that the cell voltage adds linearly by connecting the BioCells in series and a 10-cell stack developed a peak power of 750 nW (500 mV @ 2.5 μA observed at 265 kΩ. The peak power from the stack by connecting the cells in parallel was 1.4 μW (125 mV and 11.2 μA) at 1kΩ. The experimental results demonstrate that the power from a single cell can be scaled by connecting them in series and in parallel without appreciable losses. A survey of electronic devices indicated that a minimum of 20 μW will be required to run a demonstration application from a stack and also gives us the direction to scale the power output from a single cell.
Interactions Between Chemical Functionality and Nanoscale Surface Topography Impact Fibronectin Conformation and Neuronal Differentiation on Model Sol-gel Silica Substrates
Authors: Jedlicka Sabrina , Leavesley Silas J. , Little Kenneth M , Robinson J. Paul , Nivens David E. , Rickus Jenna L. 
Published: April 2011

ABSTRACTFunctional relationships between the biomaterial interface and extracellular matrix (ECM) proteins are intimately involved in cellular adhesion and function. Structural changes of ECM proteins upon adsorption to a surface alter the protein's biological activity by varying the availability of molecular binding sites. Recent work using native and organically modified sol-gel silica as a neuronal biointerface revealed that changes in surface nanotopography of bulk versus thin film materials result in dramatic differences in fibronectin structure, cell survival, and neuronal differentiation. In order to further investigate interactions between chemical functionality and surface topography, we evaluated the global conformation of human fibronectin adsorbed to seven different organically modified silica gels and thin films. Chemical functional groups were introduced into the materials either by altering the starting precursor or by doping with poly-l-lysine or polyethylenimine. Surface topography measurements by atomic force microscopy show that films have surface features less than 25 nm while bulk materials of the same precursor chemistry have features ranging from 50 – 100 nm in size. Fluorescence resonance energy transfer spectroscopy (FRET) revealed a strong interaction between surface topography and chemical functionality. Fibronectin remain globular on all bulk materials regardless of chemical modification. The same changes in precursors or dopant chemistry, however, induced changes in the conformation of fibronectin on the thin films. The differentiation of PC12 cells on the surface indicated a strong impact of the surface features and suggest a possible optimal fibronectin folding state.
Cell Viability and Adhesion on as Grown Vertically Aligned Carbon Nanotubes√
Authors: Lobo Anderson O. , Antunes Erica F. , Palma Mariana B. S. , Pacheco-Soares Cristina , Trava-Airoldi Vladimir J. , Corat Evaldo J. 
Published: April 2011

ABSTRACTThis work studies cell viability and cell adhesion on as grown dense films of vertically aligned carbon nanotubes (MWCNT). The MWCNTs were produced by a microwave plasma chemical vapor deposition (2,45GHz) on silicon (Si) and titanium (Ti) surfaces, using a nickel and iron catalyst, respectively. The citotoxicity tests (MTT assay and cellular adhesion) were evaluated by various incubations times with Fibroblast L929 mouse cells. The results show very high cell viability and many layers of cells adhered on the surface formed by the nanotubes tips at films grown on Si surfaces. The MWCNT grown on Ti surfaces presented lower cell viability and a reduced number of cells on the surface formed by the nanotubes tips. The different behavior is most probably related to excess iron contamination present in the case of titanium substrate, while nickel catalyst is probably enclosed by the nanotubes.
Decreased Macrophage Density on Carbon Nanofiber Patterns
Authors: Kim Jong Youl , Khang Dongwoo , Lee Jong Eun , Webster Thomas J. 
Published: April 2011

ABSTRACTIn this study, we describe the selective adhesion 4 hour and proliferation 24 hour and 4 days of inflammatory cells (specifically, macrophages) on aligned carbon nanofiber/nanotube patterns on a polymer matrix. The results showed for the first time that macrophage adhesion and proliferation on aligned Carbon nanofibers (CNFs) was significantly less than on the polymer matrix. The present in vitro study thus provided evidence of the ability of CNFs to down-regulate macrophage adhesion and proliferation important to decrease harmful body reaction, which is imperative for the future consideration of CNFs for numerous implant applications.
Functionalized Waveguides for Biological Assays
Authors: Anderson Aaron S. , Dattelbaum Andrew M. , Montaño Gabriel A. , Schmidt Jurgen G. , Martinez Jennifer S. , Grace W. Kevin , Grace Karen M. , Swanson Basil I. 
Published: April 2011

ABSTRACTWe report here a procedure for the functioalization of SiO2-coated, SiONx waveguides for biological assays. Surface functionalization occurs by self-assembly of an amine-terminated silane monolayer on the waveguide, followed by partial chemical modification with functionalized polyethylene glycol (PEG) groups. Functionalized surfaces were characterized by atomic force microscopy and contact angle measurements. When combined with a BSA blocking step, these functional PEG surfaces significantly reduced non-specific binding and allowed for specific binding to occur. An antibody sandwich assay for detection of Bacillus anthracis protective antigen was used to validate these surfaces for sensing applications.
Inkjet Printing of Biomedical Adhesives
Authors: Doraiswamy Anand , Sumerel Jan , Wilker Jonathan , Narayan Roger J 
Published: April 2011

ABSTRACTSynthetic adhesives have largely displaced natural adhesives in the automotive, aerospace, biomedical, electronic, and marine equipment industries over the past century. We have demonstrated the thin film deposition of biological adhesives using piezoelectric inkjet technology. A MEMS based piezoelectric actuator was controlled to jet uniform fluid flow of the adhesive solution through the ink jet nozzles. Microscopic deposition of adhesives enables improved bonding for a range of advanced electronic and biomedical applications. By printing such small and spatially aligned drops, bond lines between materials are reduced, ultimately resulting in increased bond strength and structural integrity. Piezoelectric ink jet deposition of biological adhesives may greatly improve wound repair in next generation eye repair, fracture fixation, organ fixation, and wound closure.
In vitro Evaluation of Macrophage Adhesion and Proliferation on Alumina
Authors: Liu-Snyder Peishan , Webster Thomas J. 
Published: April 2011

ABSTRACTExtensive interactions of inflammatory cells (such as macrophages) with biomaterials at the host-implant interface are often blamed for failure of implanted biomedical devices [1]. While previous studies have shown increased in vitro and in vivo bone cell (osteoblast) responses on nanophase ceramics [2], few (if any) studies have been conducted to elucidate inflammatory cell responses on such novel materials. In this study, we reported that macrophage adhesion and proliferation on nanophase (97.7 nm grain size) alumina (Al2O3) was significantly less than conventional (187.4 nm grain size) alumina, respectively, after 4, 12, 24 h. The present study provides evidence of the ability of nanophase alumina to down-regulate macrophage adhesion and proliferation, which is imperative for the future consideration of nanophase materials for orthopedic and dental applications.
Increased Osteoblast Adhesion on Nanograined Hydroxyapatite and Tricalcium Phosphate Calcium Titanate Composites
Authors: Liu Huinan , Ergun Celaletdin , Halloran John W. , Webster Thomas J. 
Published: April 2011

ABSTRACTDepending on the coating method utilized and subsequent heat treatments (such as through the use of plasma-spray deposition), inter-diffusion of atomic species across titanium (Ti) and hydroxyapatite (HA) coatings may result. These events may lead to structural and compositional changes that consequently cause unexpected HA phase transformations which may clearly influence the performance of an orthopedic implant. Thus, the objective of the present in vitro study was to compare the cytocompatibility properties of chemistries that may form at the Ti:HA interface, specifically HA, tricalcium phosphate (TCP), Ti doped HA, and those containing calcium titanate (CaTiO3). In doing so, results of this in vitro study showed that osteoblast adhesion increased with greater CaTiO3 substitutions in either HA or TCP. Specifically, osteoblast adhesion on HA and TCP composites with CaTiO3 was almost 4.5 times higher than over pure HA. Material characterization studies revealed that enhanced osteoblast adhesion on these compacts may be due to increasing shrinkage in the unit lattice parameters and consequent decrease in grain size. Although all CaTiO3 composites exhibited excellent osteoblast adhesion results, Ca9HPO4(PO4)5OH phase formation into TCP/CaTiO3 increased osteoblast adhesion the most; due to these reasons, these materials should be further studied for orthopedic applications.
Fabrication of Carbon Nanotube Langmuir-Blodgett Film by Polyion Complex Method
Authors: Matsui Jun , Iko Manabu , Inokuma Nobuhiro , Orikasa Hironori , Kyotani Takashi , Miyashita Tokuji 
Published: April 2011

ABSTRACTCarbon nanotube Langmuir-Blodgett film was fabricated using polyion complex method. Multi-walled carbon nanotube (MWCNT) synthesized by template method form a stable polyion complex monolayer at the air/water interface. The monolayer can be transferred onto a solid substrate. The AFM image of the monolayer shows a one-dimensional network structure of MWCNT..
Improvement of Emission Current by Using CNT Based X-ray Tube
Authors: Choi Haeyoung , Kim Jong Uk 
Published: April 2011

ABSTRACTStudies on the electronic structure of carbon nanotube (CNT) are of much importance because of its efficient utilization in electronic vacuum devices [1]. These CNTs have many applications such as field emission display (FED), LCD backlight units, microwave amplifiers, lighting lamps, x-ray sources and so on. One of these applications is the electron emitter for x-ray source. In order to obtain x-ray images of relatively hard instruments or components such as PCB board or machine tools, high quantity of x-ray current is generally required. In this study, we report that the current density of x-ray source can be greatly enhanced by using the CNT emitter as a cathode. In general, the emission current of CNT emitter is very sensitive to gap distance between CNT emitter and grid metal mesh. In addition, the emission current is appeared to be different with respect to the kinds of metal meshes and their sizes employed in the measurement. Extensive results of these were reported in our recent works [2]. For example, as the distance between CNT emitter and grid metal mesh was getting shorter, the current density of the triode was getting larger. Detailed parameters and corresponding results were presented and some preliminary x-ray images were obtained and discussed in this study.
Geometry Dependent Resistivity in Single-walled Carbon Nanotube Films Patterned Down to Submicron Dimensions
Authors: Behnam Ashkan , Noriega Leila , Choi Yongho , Wu Zhuangchun , Rinzler Andrew G , Ural Ant 
Published: April 2011

ABSTRACTWe demonstrate patterning of SWNT films down to 200 nm lateral dimensions using e-beam lithography and reactive ion etching with good selectivity and directionality and then we fabricate standard four-point-probe structures to characterize the resistivity of these films as a function of device geometry. The resistivity is found to be independent of device length for a given width and thickness, while increasing over three orders of magnitude compared to bulk films, as the width and the thickness of the films shrink. In particular, the resistivity of SWNT films starts to increase with decreasing device width below 20 μm, exhibiting an inverse power law dependence on device width at sub-micron dimensions. We explain this behavior by a purely geometrical argument. Although the “top-down” patterning of nanotube films allows for their use in sub-micron device structures and perhaps their integration into standard silicon fabrication technology, the resistivity scaling is an important effect that needs to be taken into account when fabricating small devices in which nanotube film transport characteristics play a vital role.
Spin-Orbital Coupling Effects on Magnetoresistance in Organic Light-Emitting Diodes
Authors: Hu Bin , Wu Yue 
Published: April 2011

ABSTRACTThe magnetoresistance of conjugated polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) based organic light-emitting diodes (OLED) was investigated at both forward and reverse bias at liquid nitrogen temperature. We find that the reverse bias yields a largely increased magnetoresistance when the electron-hole capture zone is away from the metal electrode as compared to the forward bias with the electron-hole capture zone close to the metal electrode. The electroluminescence suggests that the deposited metal atoms enhance the spin-orbital coupling at the polymer/metal interface and consequently lead to electron-hole capture zone-dependent magnetic field effects in organic semiconductor devices.
Highly Reproducible Electric Bistability in an Organic Single Layer Device with Ag Top Electrode
Authors: Terai Masaya , Fujita Katsuhiko , Tsutsui Tetsuo 
Published: April 2011

ABSTRACTHigh reproducible electrical bistability was observed and we deliberated its working mechanism through measurements of dynamic dielectric response in single organic layer sandwiched structure using top Ag electrode. The electrical transition between high-impedance state (OFF state) and low-impedance state (ON state) happened by the change of applied voltage patterns. Distinction between the OFF state and the ON state was not induced by change of static charge accumulation but reflected the difference of the response of mobile electric careers in the organic film. We proposed plausible working mechanism of transition from the pristine state to the bistable state. Namely, the electrical bistable state of our device is generated by penetration of Ag nanoparticles and creation of charge pathways across the organic film.
Molecular Multilayer Organic Solar Cells with Large Excitonic Diffusion Length
Authors: Yoo Seunghyup , Potscavage William J , Domercq Benoit , Han Sung-Ho , Levi Dean , Kippelen Bernard 
Published: April 2011

ABSTRACTWe report on the photovoltaic properties of organic solar cells based on pentacene and C60 thin films. A peak external quantum efficiency (EQE) of 69 % at a wavelength of λ = 668 nm is achieved upon optimization of the exciton blocking layer (EBL) thickness. Complex optical functions of pentacene films are measured as a function of wavelength by spectroscopic ellipsometry and used to analyze the EQE spectra. Detailed analysis of the EQE spectra indicate that the pentacene layers exhibit large excitonic diffusion lengths of ∼70 nm and that the performance improvement in EQE can be attributed to the influence of the thickness of the EBL layer on the carrier collection efficiency.
Robust Circular Polarized Emission from Nanoscopic Single-Molecule Sources: Application to Solid State Devices
Authors: Hassey Ruthanne , Swain Ellen J , Hammer Nathan I , Richards Emily L , Venkataraman Dhandapani , Barnes Michael D 
Published: April 2011

ABSTRACTControlling the polarization state of fluorescence emission in solid state devices is an important goal in optical display technologies. High-purity (right or left) circular polarized emission is particularly desirable because an arbitrary linearly polarized state can be generated with much higher efficiency (lower loss) as compared with a non-polarized fluorescence input. Here we discuss observation of resonant chiroptical effects (fluorescence detected circular dichroism (FDCD), and circular polarized luminescence (CPL)) from single (bridged-triarylamine) helicene molecules in a solid-film format. In the FDCD experiment using 457-nm excitation – an excitation wavelength where the bulk circular dichroism is negligible – single-molecule fluorescence from enantiomerically pure helicene samples show surprising distribution of dissymmetry (g) parameters centered near zero but with a significant contribution from molecules showing an almost perfectly pure response to either right or left circularly polarized light. Experiments combining a well-defined circularly polarized excitation (either right or left) with decomposition of the fluorescence into left- and right-circular polarization component show only a weak correlation between the dissymmetry (sign and magnitude) of the CPL with the polarization state of the input. Current efforts are directed at wavelength resolved CPL, FDCD at wavelengths that are more closely match to bulk circular dichroism features, and orientational dependence of FDCD and CPL. These results provide new insight into chiroptical properties of chiral fluorophores at the single molecule level and suggests new optical device possibilities with chiral fluorophores.