and Nanoelectronics and Biomedical Devices
The Hebrew University, Israel
Riga Technical University, Latvia
Title: Superconductivity and unusual magnetic behavior in nano amorphous carbon
Israel Felner has completed his PhD at the Hebrew University (HU) of Jerusalem, Israel and his postdoctoral studies at UCSD, San-Diego, California, USA (1979). Since then he works at the "Racah" Institute of Physics at the HU. He became a full professor in 1995. During 2003-2006 he served as the chairman of physics studies at the HU. He has published more than 480 papers in reputed journals and serves as an editorialboard member of three prestige scientific journals.
Traces of superconductivity (SC) up to 65 K were observed by magnetic measurements in three different inhomogeneous sulfur doped amorphous carbon (a-C) systems: (i) commercial,and (ii) synthesized powders and in (iii) a-C thin films. (i) Studies performed on commercial (a-C) powder which contains 0.21% sulfur, revealed traces of twonon-percolated superconducting phases around Tc34 and 65 K. The SC volume fraction is enhanced by the sulfur doping. (ii) Another a-C powder obtained by pyrolytic decomposition of sucrose,did not show any sign for SC above 5 K. However, mixing of this powder with sulfur and synthesize of the mixture at 400 ºC (a-CS), yields an inhomogeneous products which showstraces of SC phases at TC= 17 and 42 K.(iii) Non-superconducting a-C thin films were grown by electron-beam induced deposition. SC emerged at Tc = 34.4 K only after heat treatment with sulfur.
Other partsof the same commercial a-C and pyrolytic a-CS powders, show unusual magnetic features. (1) Pronounced irreversible peaks around 55-75 K appear in the first zero-field-cooled (ZFC) sweep only and they aretotally suppressed in the second ZFC runsmeasured a few minutes later. Their origin is not known. (2) Around the peak position the field-cooled (FC) curves cross the ZFC plots (ZFC>FC). These peculiar magnetic observations are connected to each other.All SC and magnetic phenomena observed are intrinsic properties of the a-CS materials.
It is proposed that the a-CS systems behave similarly to the high TCcurates and/or pnictides in which SC emerges from magnetic states.In addition, the a-CS system resembles the sulfur hydrides (H3S) material which becomes SC at TC = 203 K under high pressure (>200 GPa). SCinH3S is explained by the interaction between the electrons and the high frequencies hydrogen vibrations. This model may also be applied to a-CS. The relatively light nonmetallic carbon atoms and their high vibration frequencies as simple harmonicoscillatorsinduce SC even atambientpressurewithTCashig has 67K. Alternatively, it is possible that the a-Cand a-CS powders contains mall amount of hydrogen and that the observed SC states arepressedH3S embedded or adsorbed in thea-C matrix.
Meta-dielectric for energy storage
Pavel Lazarev is the inventor of Capacitor Sciences’ high permittivity technology and founder of the Company. He also is the founder of Cryscade and inventor of the company’s Donor-Bridge-Acceptor technology. He received his Masters from Moscow State University, Ph.D. in Crystallography and Dr. of Science Degree in Biophysics from the Russian Academy of Science. Previously, Pavel founded Nanotechnology MDT (www.nt-mdt.com), Akvion (www.akvion.ru), Optiva Inc., Ribtan Inc. (www.ribtan.com) and Crysoptix KK, (www.crysoptix.com). Pavel was an editor of International Journals ‘Molecular Engineering’, ‘Nanobiology’ and ‘Molecular Materials’. Pavel has published several books, over 150 technical publications and over 200 inventions with emphasis on the R&D and production of functional crystalline films based upon coatable lyotropic liquid crystals.
Energy storage units having both high energy density and high power density are important for further progress of technology. As the limitations of energy density and power density of the batteries are difficult to overcome, the right alternative solution might arrive from the capacitor technology with improved permittivity and breakdown voltage of insulating materials. In the present paper, we propose to use the engineered polymers to develop capacitors having high energy density. We believe that the proposed approach provides a new generation of the energy storage devices promising the solutions to the many needs of the society.
Polymers can be engineered to achieve significant polarizability in the frequency range of kHz-MHz, which makes such systems most suitable for the energy storage purposes. The conduction can compromise the high dielectric strength of the dielectric. To avoid this, we propose to couple the polymer cores to high resistivity materials.
In this work, we report our analysis of the feasibility to extract favorable dielectric properties based on composites of polymers.
Title: Physics underlying the negative thermal expansion of water and the computation method with extremely high accuracy
Makoto Yasutomi completed his PhD at Nagoya University in Japan. He worked in University of the Ryukyus as Instructor. He has published more than 30 papers in reputed journals.
Density of usual substances increases monotonicallywith cooling at any temperatures. But, that of water expands with reducing temperaturebelow 4℃.A number of scientists in the world have studied for centuries what causes the negative thermal expansion and a variety of ideas have been put forward up to now. Nevertheless, none of them tells us anything about what induces the negative expansion. Recently, we have succeeded in explaining the physics underlying the density anomaly. We have shown that the soft repulsion near the hard-core contact determines mainly the thermodynamic behavior of excess internal energy of water which is much different from those of usual liquids. The behavior of the internal energy causes negative thermal expansion at temperatures below 4℃. Water has also a plenty of anomalous properties other than density anomaly. In this speech, we will also talk about why water has polymorphic structures and what determines the isothermal compressibility. Today, almost all of these anomalous behaviors of water are well reproduced by numerical simulations by using realistic water models. But, it does not mean that physics underlying these phenomena are illuminated.We can derive thermodynamic properties of any substances by using thermodynamics and statistical mechanics if intermolecular forces are known. It should be said that the Physics underlying a certain phenomenon is illuminated when the relation between the phenomenon and the shape of the intermolecular potential is elucidated thermodynamically. At the present moment, Self-consistent Ornstein-Zernike approximation will be the most appropriate method to study this kind of phenomena. We have also found a computation method which makes calculation precision 1010 times higher than those presented up to now. In the study of water, we need to perform numerical computations byusing models with a variety of intermolecular interactions. Therefore, we can expect that thisextremely accurate computation method will be very useful and will bring us fruitful results.
Md Mustafizur Rahman
Title: Performance evaluation of uncoated carbide insert for end milling of aluminium alloy (6061 T6) with nanofluid MQL environment
Professor Dr. Md. Mustafizur Rahman is a consultant, a researcher currently working with the Faculty of Mechanical Engineering, Universiti Malaysia Pahang, Malaysia since April 2007. Dr. Rahman also served as a Deputy Director as well as acting Director in the Automotive Engineering Centre, UMP. He received his Ph.D. degree from the Department of Mechanical and Materials Engineering, Universiti Kebangsaan Malaysia. The research work of Dr. Rahman is focused on advanced machining, optimization, finite-element analysis, modeling of modern materials, nanofluids in machining applications, nanofluids in ICE. He has published more than 290 papers in international scholarly journals and conferences. He is also the member of Editorial Boards of seven scientific journals, including Editor-in-Chief, International Journal of Automotive and Mechanical Engineering (Scopus Index) and Journal of Mechanical Engineering and Sciences (Scopus Index). He has been the technical reviewer for over 25 scientific journals as well as the member of the technical board for conferences. He is fellow of Association of Computer, Electronics and Electrical Engineers (ACEEE) and Indian Society of Mechanical Engineers (ISME), senior members of American Society of Mechanical Engineers (ASME) and International Association of Computer Science and Information Technology (IACSIT), founder member of Malaysian Society for Engineering and Technology (mSET) and also members of several professional societies such as Institute of Engineer, Bangladesh (IEB); Bangladesh Society of Mechanical Engineers (BSME); International Association for Computation Mechanics (IACM); Malaysian Association of Computational Mechanics (MACM); International Association of Engineers (IAENG). He has been supervising nine PhD and 16 M.Sc. Eng. Candidates (by research) and more than 55 undergraduate dissertations.
Cutting fluids are considered essential for a number of reasons such as decreasing friction between the workpiece and the cutting tool, reducing the tool wear thus enhancing the tool life and improving the surface characteristics, lubricating and cooling the interface between sliding surfaces, increasing productivity due to reduced costs through minimizing the heat generated at the mated surfaces and for flushing away the chips, debris and residues. Uncoated cemented carbide tools are tested for performance analysis in terms of flank wear in end milling of aluminium alloy AA6061 with a minimum quantity lubrication condition using TiO2 nanofluid. The results of the machining with water-based TiO2 nanofluid are compared with oil-based minimum quantity lubrication phenomena. Micro-abrasion, micro-attrition and adhesion wear leading to edge chipping are identified as the main wear mechanisms. Aluminium deposits as a result of adhesion and attrition on the tool flank regionare observed. The results show the capabilities of water-based nanofluid as a competent MQL medium, in terms of tool edge integrity and reduced adhesion losses, replacing the conventional oil-based MQL.
Keywords: MQL, nanofluid, wear, abrasion, attrition, adhesion
Asiful Hossain Seikh
Title: Corrosion resistance behavior of newly fabricated nanocrystalline Al-Fe-Cr alloy produced by mechanical alloying and High Frequency Induction Sintering
Dr. Asiful Hossain Seikh is an experienced result oriented Researcher with a professional background comprising 18years of research, technical and supervisory experience in materials, corrosion, mechanical, chemical and metallurgy engineering. His areas of technical experience include materials/polymer research and testing, failure analysis, materials specification and selection, corrosion control and monitoring, paints and coating evaluation, inhibitor evaluation and chemical treatment. Dr. Seikh has completed his Bachelor degree (1994) in Materials & Metallurgy from National Institute of Technology, Durgapur, India and Master (1997) & PhD (2005) in Materials & Metallurgical Engineering from Jadavpur University, Kolkata, India. During his professional career in KACST (2003-2005), Riyadh, KSA, UAE University (2005-2010), Al Ain, UAE and King Saud University (2011-Present), he has been involved in a number of research and industrial projects related to corrosion and metallurgy. Based on the results of his research work, a number of research papers (20 Journals & 6 Conferences) have been published.
In this study, nanocrystalline aluminium alloy was produced from metallic powders with addition of 10wt. %Fe and 5wt. %Cr processed using mechanical alloying (MA) technique. The initial powders were processed in a planetary ball mill for 150 hours at room temperature in an inert atmosphere. The processed powders were consolidated and sintered using a high frequency induction heat sintering (HFIHS) machine to form bulk samples. The crystallize size of the bulk samples was calculated from the peak profile obtained through X-Ray diffraction (XRD). The corrosion resistance of nanocrystalline aluminium alloy was studied in 3.5% NaCl solution at room and higher temperatures using electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) techniques. Linear polarization resistance curves, Nyquist data and Bode curves obtained by electrochemical impedance spectroscopy, suggest that the alloy have good resistance to corrosion in sodium chloride solution at room temperature as well as at higher temperatures.
Keywords: Nanocrystalline aluminium alloy, mechanical alloying, corrosion, polarization, EIS
Chen-Chi M Ma
Title: Mechanical and dielectric properties of polyhedral oligomeric silsesquioxanes modified graphene oxide/polyimide nanocomposites
An effective method is proposed to prepare octa(aminophenyl) silsesquioxane (OAPS) functionalized graphene oxide (GO) reinforced polyimide (PI) composites with a low dielectric constant and ultra-high mechanical properties. The amine-functionalized surface of OAPS-GO is a versatile starting platform for in situ polymerization, which promotes the uniform dispersion of OAPS-GO in the PI matrix. Compared with GO/PI composites, the strong interfacial interaction between OAPS-GO and the PI matrix through covalent bonds facilitates a load transfer from the PI matrix to the OAPS-GO. The OAPS-GO/PI composite film with 3.0 wt% OAPS-GO exhibited an 11.2-folds increase in tensile strength, and a 10.4-folds enhancement in tensile modulus compared with neat PI. The dielectric constant (Dk) decreased with the increasing content of 2D-porous OAPS-GO, and a low Dk value of 1.9 was achieved.
Keywords: Graphene, Nanocompsites
Berhanu Tulu Kacha
Title: Resistive switching characteristics of 11nm-thick metal oxide thin film for nonvolatile memory applications
Berhanu Tulu Kacha was born in Gondar, Ethiopia. He received B. Sc. in Physics, from Bahir Dar University, Ethiopia, in 2002, M.Sc. in Solid State Physics, from Addis Ababa University, Ethiopia, in 2005 and his Ph.D. in Materials Science and Engineering, from National Taiwan University of Science and Technology, Taiwan, in 2014. He worked as a Physics Lecturer in Maichew Technique College and Gondar Teachers College, Ethiopia 2002-2007. Then he joins University of Gondar as a Physics Lecturer. After he finished his PhD in 2014, he is a Professor in University of Gondar. Currently, he is staff member in the Department of Physics, College of Natural and Computational Science, and Head of Nanotechnology Research Center at University of Gondar.
Memory device is one of the most important products in the electronics market. To satisfy the needs of various current commercial electronic devices, such as computers, digital cameras, smart mobile phones and etc., non-volatile memories (NVMs) with huge storage capacities are needed. To overcome the problems of current NVM concepts, a variety of alternative memory concepts is explored. Among those memories, Resistive Random Access Memory (RRAM) NVMs based on electrically switchable resistance have attracted considerable attention. RRAM has gained significant interest as one of the most promising candidates as a next generation NVM device.
In this paper, resistive switching (RS) characteristics and mechanism of metal oxide RRAM device are studied. Based on an amorphous (ZrCu)Ox active layer with a thin thickness of ~11nm is sputter deposited without substrate heating or post-annealing. The device shows forming-free unipolar RS properties of low operation voltage (<1.7V), long retention time, good endurance and resistance ratio. The RS property is considered to be dominated by the filamentary conduction due to the presence of oxygen vacancies in the grain boundary-free structure.
Keywords: Resistive Random Access Memory (RRAM), resistive switching, metal oxide, sputter deposited and oxygen vacancy.
Irene S Fahim
Title: Nanoindentation investigation on chitosan thin films with different types of fillers
Irene Samy is an adjunct professor, Mechanical Engineering department, The American University in Cairo (AUC), Cairo, Egypt. She is also teaching as a full time professor and the director of the nanotechnology program in Nile University, Cairo, Egypt . Her PhD thesis project is developing novel polymer composites membranes for industrial applications. She earned her Masters of Material Science, Mechanical Engineering. AUC. The Master’s Thesis project was developing natural fiber (rice straw) reinforced composites. Irene is a board member in Metal Tube S.A.E. company for manufacturing steel tubes and scaffolds and a board member in the Egyptian society (New Cairo British International School. Also a member, in the American Chamber of commerce and Egyptian National Network Nanotechnology. Moreover, she is a member in the Royal Society of Chemistry. Irene has nine publications in the area of polymer nanocomposites and sustainability. Irene attended four conferences as an oral presenter.
Chitosan nanocomposite thin films were fabricated by dispersing two types of chitosan natural polymer( crosslinked chitosan (CLCS) and non crosslinked chitosan(NCLCS)) , with nanofillers (graphene (G)and fullerene (F)) at three different weight %. Nanoindentation tests were performed to investigate the nano mechanical properties of the fabricated nanocomposite in comparison to the monolethic chitosan thin films. It was clearly obvious that the change in the size of indenters affected the penetration surface area of the thin films. Young's modulus (E) and nano hardness values (H) were calculated using 5, 10 µm spherical indenters. CLCS/ 1 wt % F showed a significant improvement on the E and H values. While the NCLCS/1 wt. G showed a significant improvement on the E and H values.
Title: Trapping and analyzing particles with Optofluidics’ NanoTweezer
Ms. Li is technical sales and marketing lead at Optofluidics. She earned 2 Master’s Degree (Materials Science & Electrical Engineering) from UPenn and her Bachelor’s Degree of Materials Science from Tsinghua University.
We present the market’s latest particle analysis system. The NanoTweezer Surface uses cutting edge nanophotonics and microfluidics to analyze nanoscale particles in solution, chiefly characterizing their size and their surface properties, simply not possible with current instrumentation. The device uses near field optics to impart optical forces that drive the particles to interact against a reference surface, and by measuring the amount of light these particles scatter, the NanoTweezer Surface characterizes the interaction potential to infers the surface properties of the particle. Researchers are using our tool in nanomedicine and nanotoxicity to measure weak and non-ionic interactions such as those imparted when a particle is PEGylated, as well as assess ligand coverage during surface functionalization. The system allows researchers to better assess formulation stability, particle surface coverage and offers key new insights to make better colloidal systems. We will dive into the device physics as well as offer case studies.
Printable stretchable electrodes based on silver nanowires
Teppei Araki received his Ph.D. in engineering from Osaka University at September 2014 under supervision of Prof. Katsuaki Suganuma for “printable wiring technology for stretchable electronics”. He was a JSPS Fellows and studied at Holst Centre in the Netherland for a year during doctoral program He works as an assistant professor of Osaka University from October 2014 and engages in “flexible electronics and photonics” supervised by Prof. Tsuyoshi Sekitani.
Tsuyoshi Sekitani received the B.S. degree from Osaka University, Japan in 1999, and the Ph.D. degree in applied physics from the University of Tokyo, Japan in 2003. From 1999 to 2003, he was with the Institute for Solid State Physics, the University of Tokyo. From 2003 to 2010, he was a Research Associate, and in 2011, he was an Associate Professor in the School of Engineering at the University of Tokyo. In 2014, he was made a Professor in The Institute of Scientific and Industrial Research at Osaka University. His current research interests include organic transistors, flexible electronics, plastic integrated circuits, large-area sensors, and plastic actuators.
Silver nanowires (AgNWs) have attainedmyriad performances due totheir structure of the high aspect ratio and twin crystal. A transparent electrode based on aAgNWs network is one of candidates for an alternative to tin-doped indium oxide (ITO). Although ITO have been widely used in displays, touch screens, and solar cells, there are limitation of supply and brittleness. The AgNWs transparent electrode shows high flexibility in addition to comparably optical transmittance and electrical resistance of an ITO film. This can pave the way for future flexible and wearable electronics which can be bent, stretched, compressed, and twisted to arbitrary shape.Moreover, simple solution preparation of AgNWs, so-called polyol methods, have a possibility resulting into high throughput roll-to-roll process which is a printing technique of creating electronic devices on flexible plastic or metal foils. Here, ultra-long AgNWs were synthesized by modifying polyol method to improve the transmission haze and optical transmittance of the transparent electrode. A transparent electrode based on the ultra-long AgNWs achieved an electrical sheet resistance of 1×102 Ω/□, and low transmission haze of 2.6% with a high parallel optical transmittance of 95%. Patterning large/small area of stretchable/transparent electrode will also be presented.
Surface patterning of n-octadecyltrichlorosilane (OTS) self assembly monolayers: Constructive nanolithography
Dr. Peter N. Nelson Completed his A.Sc., (2007) in Chemistry and Biology from the College of Agriculture, Science and Education (C.A.S.E) followed by his B.Sc., (2009) in general chemistry and Ph.D (2013), in physical chemistry, from the University of the West Indies, Mona. His PhD work was focused on adducing the molecular structures and phase properties of some solid state anhydrous metal carboxylates. This work was carried out under the guide of Professor Henry A. Ellis; one of the founding fathers of that area. He is now a postdoctoral fellow at the Weizmann Institute of Science (WIS) in the department of Materials and Interfaces. His work at WIS, under the guide of Professor Jacob Sagiv; the father of Molecular Self Assembly, is focused on nanofabrication via AFM and e-beam lithography. Currently, his research interests include, but are not limited to, thermodynamics, Quantum dots, nanoionics and AFM lithography.
Constructive nanolithography; a generic bottom-up fabrication technique, developed in our laboratory, capable of producing high resolution active surface features on the otherwise inert outer surface of self-assembled OTS monolayers, provides invaluable opportunities for the advancement of surface bound ultra-low dimensional electronics and surface bound macromolecular architectures. The recent fabrication of a quasi two dimensional electrolytic cell, facilitated by low humidity surface ionic conduction on pre-planned carboxylic acid nanowires,inscribed on the surface of OTS monolayersvialocal AFM probe electrooxidation, highlights the significance of this work. Unfortunately, concomitant partial monolayer destruction occurred with the oxidativetransformation of methyl functions to carboxylic acid during pattern inscription.3However, our more recent results show that the outer surface of OTS can be locally oxidized with humidities above 30 % and applied voltages of above -5.9 V; that is, the undesired oxidation of the underlying silicon substrate occurs only above -6.4 V, at minimum set-point, where the height of the resulting silicon oxide increases linearly as does the dimensions (width in the case of lines)of the inscribed features. Voltages between -6.1 to -6.4 result in no oxidation of the substrate, in addition to accurate and continuous surface patterns. Highset-points (> 0.4 nA) result in lateral broadening of the water meniscus, adsorbed to the surface of the AFM probe, hence, there is broadening of the inscribed patterns and increased oxidation of the underlying substrate. Competition between the kinetics of water adsorption to the probe and that for the combined consuming processes: evaporation and reaction, result in discontinuous patterning at high inscription rates, ca.>1 µm/s; that is, the overall consumptionrate becomes greater than the former at this speed. Indeed, the aforementioned conditions can be reproducibly used for the generation of high resolution surface patterns (lines) with dimensions (widths) below 35 nm using a 40 nm (Probe radius) inscription probe. After pattern inscription, contact and semi-contact measurements, using high resolution probes under low humidity conditions, must be combined to obtain accurate imaging, facilitating reliable dimensional analysis. High resolution localized oxidation of the OTS monolayer surface is described by a minimal difference between the friction of the pattern on trace and retrace. These patterns are highly sensitive to moisture, resulting in local variation of surface frictional forces, hence, measured pattern dimensions are moisture sensitive.
Saad M Alshehri
Fabrication of High-performance supercapacitor electrode based on a polyaniline and N-doped activated carbon
Polyaniline (PANI) and mesoporous activated carbon are used to fabricate a supercapacitor electrode material with enhanced electrochemical performance. The chemical and structural properties of the electrode are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy with confirmation of a semi-crystalline nature. The homogeneous growth of PANI on the meso porous carbon is visualized by field emission scanning electron microscopy (FESEM) and shows the morphology. The maximum specific capacitance of the nanocomposite electrode is found to be ∼980 F g−1 in 1 M H2SO4 within the potential window of −150 to 800 mV vs. Ag/AgCl at 10 mV s−1 scan rate (∼1002 F g−1 at 1 mA cm−2 discharge current density). The high surface area offered by the conducting, N-doped mesoporous carbon stimulates effective utilization of the deposited PANI and improves electrochemical charge transport and storage. The super capacitor derived nanoporous materials exhibit excellent electrochemical performance with high specific energy and specific power, and excellent cycling stability.
Keywords: Polyaniline, supercapacitor, XRD, nanoporous carbon