eLearning

Behavior of water droplet on polymer material and the influence on discharge characteristics

N. Arise; H. Nishioka; Y. Okraku-Yienkyi; M. Otsubo; C. Honda 1999 Annual Report Conference on Electrical Insulation and Dielectric Phenomena (Cat. No.99CH36319), 1999

To clarify the influence of a water droplet on discharge characteristics, water droplet was put on the polymer and the current and voltage characteristics of corona discharge was investigated under the application of AC voltage, using two different types of electrode systems (plane with needle to plane, needle to plane). The behavior of the water droplet was also investigated by ...

Fiber-optic pH sensors fabrication based on selective deposition of Neutral Red

Carlos R. Zamarreño; Miguel Hernáez; Ignacio R. Matías; Francisco J. Arregui 2009 IEEE Sensors, 2009

In this work, a novel application of the electric field directed layer-by- layer self assembly (EFDLA) selective deposition method for the fabrication of optical fiber pH sensors is presented. Here, indium tin oxide (ITO) coated optical fibers have been fabricated via a dip-coating deposition method. These fibers are used as electrodes in the EFDLA protocol in order to deposit selectively ...

Widely Wavelength-Tunable Mode Converter Based on Polymer Waveguide Grating

Yu Yang; Kaixin Chen; Wei Jin; Kin Seng Chiang IEEE Photonics Technology Letters, 2015

We design and fabricate a corrugated grating on a polymer waveguide for the realization of the conversion between the fundamental mode and the higher order mode. The transmission characteristics of the device are insensitive to the polarization state of the input light. Our typical fabricated device shows a mode conversion efficiency higher than 99% over a bandwidth of ~4 nm ...

Photoresponsive interpenetrating network photonic crystal

Marta K. Maurer; David E. Condon; Heather E. McKinney; Jin-Kwang Kim 2009 IEEE Sensors, 2009

We have developed a photonic crystal-based hydrogel which changes volume upon exposure to light and possesses unique optical properties. The photoswitchable material was created by embedding a crystalline colloidal array into a polyacrylamide network, and then infusing a second network, consisting of an azobenzene derivative, disperse red 1 methacrylate monomer, into the first network. We observed a 55 nm diffraction ...

Synthesis and properties of conducting polymers from propargylammonium salts by transition metal catalysts

Y. S. Gal; B. Jung; W. C. Lee; S. K. Choi International Conference on Science and Technology of Synthetic Metals, 1994

Summary form only given. Novel conjugated ionic polymers from propargylamonium bromides were synthesized and characterized. The ionic monomers used are as follows: HC/spl equiv/CCH/sub 2//sup +/NH/sub 3/Br/sup -/, HC/spl equiv/CCH/sub 2//sup +/N(CH/sub 3/)2(CH/sub 2/Ph)Br/sup -/, (HC/spl equiv/CCH/sub 2/)/sup 2//sup +/NH2Br/sup -/. These monomers were easily polymerized by PdCl/sub 2/ and PtCl/sub 2/ to give a high yield of polymer. In ...

IEEE-USA E-Books

• Space Charge in HVDC Extruded Insulation: Storage, Effects, and Measurement Methods

  This chapter discusses space-charge storage in HVDC extruded insulation, the relevant manifold effects, and the techniques developed by researchers in order to measure the amount and distribution of space charge stored in the insulation, and the electric field profile associated with such distribution. It reviews the theoretical background of charge injection and transport in insulating polymers. The chapter illustrates the processes that result in space-charge accumulation namely charge generation - via electronic charge injection, field-assisted thermal ionization of impurities, spatially inhomogeneous electric polarization, and steady DC current coupled with a spatially varying ratio ofpermittivity to conductivity. It also reviews the space-charge measurement methods for HVDC extruded insulation. The chapter focuses on the up-to-date developments of the best-suited techniques for measuring space charges in extruded insulation for HVDC cables. It provides a comparison between the best space-charge measurement methods for power cables: pulsed electro acoustic (PEA) versus thermal step method (TSM).

• Processing Integrated Capacitors

  This chapter contains sections titled: Sputtering CVD, PECVD and MOCVD Anodization Sol-Gel and Hydrothermal Ferroelectrics Thin- and Thick-Film Polymers Thick-Film Dielectrics Interlayer Insulation Interdigitated Capacitors Capacitor Plate Materials Trimming Integrated Capacitors Commercialized Integrated Capacitor Technologies Summary References

• Cold Plasma Processes for Surface Modification

  This chapter contains sections titled: Introduction Surface Modification of Polymers Surface Cleaning and Ashing Oxidation Surface Hardening Questions References

• Optical CrossConnects

  This chapter contains sections titled: Introduction Optical Cross-Connect Model Free Space Optical Switching Solid-State Cross-Connects Microelectromechanical Switches: Reflector Type Electromechanical Switches: Mirror Array Switching Speeds Polymers Photochromic Materials This chapter contains sections titled: Exercises

• No title

  Cardiac tissue engineering aims at repairing damaged heart muscle and producing human cardiac tissues for application in drug toxicity studies. This book offers a comprehensive overview of the cardiac tissue engineering strategies, including presenting and discussing the various concepts in use, research directions and applications. Essential basic information on the major components in cardiac tissue engineering, namely cell sources and biomaterials, is firstly presented to the readers, followed by a detailed description of their implementation in different strategies, broadly divided to cellular and acellular ones. In cellular approaches, the biomaterials are used to increase cell retention after implantation or as scaffolds when bioengineering the cardiac patch, in vitro. In acellular approaches, the biomaterials are used as ECM replacement for damaged cardiac ECM after MI, or, in combination with growth factors, the biomaterials assume an additional function as a depot for prolong d factor activity for the effective recruitment of repairing cells. The book also presents technological innovations aimed to improve the quality of the cardiac patches, such as bioreactor applications, stimulation patterns and prevascularization. This book could be of interest not only from an educational perspective (i.e. for graduate students), but also for researchers and medical professionals, to offer them fresh views on novel and powerful treatment strategies. We hope that the reader will find a broad spectrum of ideas and possibilities described in this book both interesting and convincing. Table of Contents: Introduction / The Heart: Structure, Cardiovascular Diseases, and Regeneration / Cell Sources for Cardiac Tissue Engineering / Biomaterials: Polymers, Scaffolds, and Basic Design Criteria / Biomaterials as Vehicles for Stem Cell Delivery and Retention in the Infarct / Bioengineering of Cardiac Patches, In Vitro / Perfusion Bioreactors and Stimulation Patterns in Cardiac T ssue Engineering / Vascularization of Cardiac Patches / Acellular Biomaterials for Cardiac Repair / Biomaterial-based Controlled Delivery of Bioactive Molecules for Myocardial Regeneration

• OLED Materials

  OLED performance is largely dependent upon OLED materials. This chapter describes the classification of OLED materials and typical OLED materials.OLED materials are divided into two types ??? vacuum evaporation type and solution type ??? from a process point of view. Vacuum evaporation materials are usually small molecular materials, while solution type materials contain polymers, dendrimers, and small molecular materials. In addition, materials are also divided into fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescent (TADF) materials in terms of emission mechanisms. From the function point of view, OLED materials can be classified as hole injection material, hole transport material, emission material, host material in emissive layer, electron transport material, electron injection material, charge blocking material, etc.Anode and cathode materials are also important, so this chapter also describes anode and cathode materials.In addition, this chapter describes molecular orientations of organic materials because this also influences OLED characteristics.

• Micro- and Nanotechnologies to Engineer Bone Regeneration

  In this chapter, selected published articles pertaining to micro- and nanotechnologies for bone tissue engineering are reviewed with a focus on development of scaffolds. Nanoparticles and nanofibers have shown to improve the mechanical properties of biodegradable polymeric implants. Non-union bone fractures are a major health care concern in the United States. One of the most widely used strategies in bone tissue engineering is the use of scaffolds for temporary structural support. Scaffolds are porous biomaterials and play a central role in tissue engineering approaches by guiding cell proliferation and assisting the exchange of nutrients and waste. Scaffolds made with micro- and nanoparticles and micro- and nanofibers show much promise as they impart the ability to create scaffolds with appropriate mechanical properties and microenvironment. The chapter discusses micro/nanomaterials of hydroxyapatite, a variety of synthetic polymers, and silk, and their potential for use as bone tissue engineering scaffolds.

• Materials for Microelectronic Packaging

  This chapter contains sections titled: Introduction Some Important Packaging Material Properties Ceramics in Packaging Polymers in Packaging Metals in Packaging Materials Used in High-density Interconnect Substrates Summary This chapter contains sections titled: References Exercises

• Embedding Compounds

  This chapter contains sections titled: Introduction Critical Properties Fillers Federal Specification MIL-I-16923 ASTM Standard for Embedding Compounds Embedding Processes Curing Systems Development Programs Market Trends Comparative Characteristics of Encapsulants Principal Embedding Polymers for Electrical/Electronic Uses

• Will Composite Nanomaterials Replace Piezoelectric Thin Films for Energy Transduction Applications?

  Semiconducting piezoelectric nanowires (NWs) show significant potential for application in electronic and electromechanical sensors and energy harvesters. In particular, these nanostructures can be used to build composite piezoelectric materials that could offer several advantages when integrated vertically. First, NWs of various lengths opens the possibility to fabricate composite layers thicker than standard thin films (<4 ??m). Second, low???temperature fabrication process make this technology compatible with CMOS devices and with different substrates, such as Si, polymers, plastics, metal foils, and even paper. Third, properties such as piezoelectricity, flexibility, and dielectric constant can be improved in NWs, thereby improving the performance of NW???containing composite materials. Finally, FEM simulations show that composites can provide better performance compared to piezoelectric thin films of the same thickness, and that performance can be improved by operating in compression or flexion modes by the right choice of the dielectric matrix and NW density.