bluuebunny/crossref_metadata_2025 huggingface dataset:
New Multimode Sensors Based on Nanostrucured Materials for Simultaneous Screening of Biological Fluids for Specific Breast Cancer and Hepatitis B Biomarkers
Authors: Stefan - van Staden Raluca Ioana , Enachescu Marius
Published: March 2013

New materials (e.g., dextrins) were proposed for the design of multimode sensors for screening of biological fluids for specific biomarkers for breast cancer antigen and hepatitis B. The selection of the materials was based on its nanostructure (for stochastic mode), and its catalytic activity (for amperometric mode). The qualitative analysis was performed using the stochastic mode, and it was followed by the quantitative analysis of the antigens using stochastic mode and amperometric mode. The biomarkers were determined directly from the biological fluids (e.g., whole blood). The response characteristics of the new multimode sensors for CA15-3, and hepatitis B biomarkers (HBV antigen and D-pipecolic acid) as well as their recovery in the biological fluid of the patients are shown.
Performance of Optimized Phage-Based Magnetoelastic Biosensors for Salmonella Typhimurium Detection on Tomatoes
Authors: Park Mi-Kyung , Li Suiqiong , Weerakoon Kanchana , Horikawa Shin , Chai Yating , Hiremath Nitilaksha , Petrenko Valery A , Chin Bryan A.
Published: March 2013

An optimized, phage-based magnetoelastic (ME) biosensor method was performed to detect Salmonella Typhimurium contaminates on the surface of tomatoes and to determine the detection limit. After serial inoculations of S. Typhimurium on the surface of the tomatoes, the S. Typhimurium on the surfaces was analyzed using an optimized ME biosensor method. Detection limit and sensitivity of the ME biosensor for detection of S. Typhimurium on tomatoes were determined. The resonant frequency shifts of the ME measurement sensors increased linearly with an increase in the concentration of S. Typhimurium. Contrastingly, the control sensors showed relatively constant and low magnitude frequency shifts. Detection limit and sensitivity of the ME biosensor method was determined to be (1.78 {plus minus} 0.17) log CFU/cm2 and 922.7 Hz.
Fabrication of Minimally-Invasive Patch Type Glucose Sensors
Authors: Yasuzawa Mikito , Sato Shinya , Nakanishi Hiroshi , Edagawa Kazuaki
Published: March 2013

A fine tube type glucose sensor, which has a sensing region at the inside wall of fine tube tip, was prepared and applied for minimally invasive glucose monitoring. The enzyme glucose oxidase was immobilized on the platinum surface located in the tube by the combination of electrodeposition and electropolymerization of o-phenylenediamine. Amperometric responses of the prepared electrodes to glucose were measured at a potential of 0.60 V (vs Ag/AgCl). The tube type electrode showed good response with good linear relationship up to the glucose concentration of 22.4 mM, which was actually higher than general sensor without outer film for permeability restriction. This may be due to it unique sensor structure.
Flexprint Substrate Enzyme Sensor for Determination of Daily Glucose-Profiles of Diabetic Patients
Authors: van der Wal Peter Douwe , Hadvary Paul , Tschirky Hans-Jörg , de Rooij Nico F.
Published: March 2013

The goal of our project is to develop a miniaturized system allowing continuous measurement of glucose concentration profiles over 24 hours for several days. The unique feature of the PharmaSens / IMT approach lies in the insertion mechanism and the needle size to assure optimum user-friendliness and patient comfort. The measurement method is based on classical amperometric detection using an enzymatic membrane. The sensor substrate is made on a flexprint substrate and consists of a 3-electrode cell on a needle-shaped tip of ~100 µm width and is covered with polymeric membranes. The sensor is integrated in a device that combines the insertion mechanism and electronics, not needing a separate insertion tool.
Rapid and Simple Immunoassay Based on Negative Dielectrophoresis with Three-Dimensional Interdigitated Array Electrodes
Authors: Yasukawa Tomoyuki , Shiku Hitoshi , Matsue Tomokazu , Mizutani Fumio
Published: March 2013

Rapid accumulations of particles and living cells with negative dielectrophoresis (n-DEP) have been applied to develop the rapid and simple immunosensing method. Grid formation of electrodes was fabricated by rotating the upper template interdigitated microband array (IDA) electrode by 90º relative to the lower IDA. When AC electric signal was applied to the bands on the upper and lower IDA, island organization was rapidly formed at the intersections with low electric fields. The accumulated particles were fixed through the immunoreactions between the antibody immobilized on the particle surface and analytes in the solution. The presence of the specific antigens allowed the formation of fixed complexes of particles. It is noted that the time required for single sensing is as short as 5 min and separation steps are eliminated in the presented procedure. We demonstrated the rapid and simple immunosensing using the aggregation of particles accumulated with DEP.
High-Throughput Separation Assay for NO Metabolites in Blood Using Microfluidic Electrophoresis
Authors: Wakida Shin-ichi , Miyado Takashi , Shimazu Kiyoko , Shibutani Yasuhiko , Mizukami Tomoe , Nose Kazutoshi , Shimouchi Akito
Published: March 2013

As an alternative NO assay based on Griess method, we investigated a high-throughput separation assay of NO2- and NO3- in human blood using an electrophoretic Lab-on-a-Chip with UV detection directly. To measure the NO metabolites in real human blood, we optimized the running buffer condition of an on-chip pre-concentration technique, transient isotachophoresis (tITP) and also the applied voltage for microfluidic control for a new dry-etched quartz glass chip in detail. We achieved acceptable sensitivity for the rapid NO metabolite separation assay with 6.5 seconds and 25 seconds for separation and sample introduction, respectively. As a result for the tITP application, the limits of detection for NO2- and NO3- in human pooled serum were improved to be 2.3 mM from 5.0 mM and 9.1 mM from 14.2 mM, respectively. We also challenged blood plasma assay.
Effects of Surface Modification of Noble-Metal Electrodes with Au on the H2-Sensing Properties of Diode-Type Gas Sensors
Authors: Hyodo Takeo , Yamashita T. , Shimizu Y.
Published: March 2013

Diode-type TiO2 film gas sensors equipped with noble-metal (Pd or Pt) electrodes (M/TiO2, M = Pd or Pt) have been fabricated, and the effects of surface modification of the electrodes with Au on their H2-sensing properties have been investigated at 250oC in both air and N2 under dry and wet atmospheres. H2 response of M/TiO2 sensors in dry N2 was much larger than that in dry air, but the surface modification of the Pd or Pt electrode with Au (Au/Pd or Au/Pt) improved the H2 response, especially in dry air. In addition, the sensor with the Au/Pt electrode showed large and O2-independent H2 response under wet atmosphere.
Solid Electrolyte Type Ammonia Gas Sensor with High Water Durability
Authors: Tamura Shinji , Nagai Tsukasa , Imanaka Nobuhito
Published: March 2013

Highly water durable ammonia gas sensor was fabricated by the combination of Al3+ ion conducting (Al0.2Zr0.8)20/19Nb(PO4)3 solid electrolyte and NH4+-β-gallate (NH4+-Ga11O17) auxiliary sensing electrode, and its NH3 gas sensing performance was investigated in humid atmospheres. The present sensor showed an advanced sensing performance of continuous, quantitative and reproducible response which obeys the theoretical Nernst relationship even in a highly humidified condition containing 4.2 vol% H2O at 230 {degree sign}C.
Direct Comparison of Anti-Interference Property for Bimetallic PtAu, PtIr, and PtRu Nanoparticle Catalysts in Amperometric Detection for H2O2 Based Biosensors
Authors: Janyasupab Metini , Zhang Yuan , Liu Cheng-Wei , Liu Chung-Chiun
Published: March 2013

Platinum based bimetallic nano electrocatalysts such as PtAu, PtIr and PtRu appear to be very unique toward H2O2 oxidation due to their composition, morphology, shape, surface active site and other properties. Enzymatic reactions often produce H2O2 as a by-product. Therefore, an electrocatalyst reacts favorably with H2O2 will enhance the detection of the analyte in biosensing. This study describes the synthesis and characterization of these bimetallic electrocatalysts and their electrochemical oxidation with H2O2 and their reactions with essential interference species, such as ascorbic acid, uric acid and others. A minute interference by PtIr and PtRu nano electrocatalysts are found minimizing the effect contributed by ascorbic acid, uric acid, dopamine and acetaminophen. The results of this study will aid in the design of H2O2 sensing based biosensors using the platinum based bimetallic electrocatalysts enhancing their performance.
A High-Throughput Assay for Evaluation of Embryoid Bodies Using Local Redox Cycling-Based Electrochemical Chip Device
Authors: Ino Kosuke , Nishijo Taku , Kanno Yusuke , Shiku Hitoshi , Matsue Tomokazu
Published: March 2013

We have previously proposed an excellent method to incorporate many electrochemical sensors into a single chip device using two sets of microelectrode array to induce local redox cycling, and we have designated the novel methodology as local redox cycling-based electrochemical (LR-EC) system. In this study, we developed a LRC-EC chip device consisting of 256 electrochemical sensors. At the electrochemical sensors, ring-type interdigitated array (IDA) electrodes were placed to induce local redox cycling. The LRC-EC chip device was applied to evaluate three-dimensional (3D) culture cells, such as embryoid bodies (EBs).
Printed Amperometric Gas Sensors
Authors: Carter Michael T , Stetter Joseph R. , Findlay Melvin W. , Patel Vinay
Published: March 2013

A new type of amperometric gas sensor, based on screen printing and lamination strategies, has been fabricated and tested. These sensors use thin film electrodes, printed on plastic substrates to form a small, low power (μW) amperometric sensor package, which uses a very small volume of electrolyte. These sensors have been demonstrated to have improved performance compared to amperometric gas sensors of conventional design, when conventional electrolytes are used. The sensors have also been demonstrated to have promising performance, compared to conventional technology, using room temperature ionic liquid electrolytes (RTILs). The printed sensors have been demonstrated successfully for monitoring of carbon monoxide (CO), ammonia (NH3).
Development of Micro Hydrogen Gas Sensor Utilizing Polymerized Gel with Ionic Liquid as a Solvent
Authors: Yamauchi Takeshi , Matsui Taku , Nishiyama Takashi , Tsunashima Katsukiko , Tsubokawa Norio , Harada Shuji
Published: March 2013

In this study, the gel beads contained ionic liquid were applied to electromotive force (EMF) hydrogen sensor which has a high hydrogen gas detecting ability. Ionic gel beads were prepared by suspension polymerization and their diameters were 100-2000 μm. The sensor utilizing ionic liquid gel has flexibility and heat endurance. The weight and shape of gel beads were maintained not only in high temperature condition but also under vacuuming condition. The hydrogen micro sensor was able to detect 2 % hydrogen concentration. It has high grade gas selectivity and can detect hydrogen gas in the range of explosion limit. It is considered that the sensor can be used as superior hydrogen sensor.
The Influences of Quenching Times on the Property of Thermal Oxidized Iridium pH Sensor
Authors: Huang Feifei , Jin Ying , Wen Lei , Mu Daobin , Cui Mengmeng
Published: March 2013

The iridium/iridium oxide pH sensors were fabricated by thermal oxidation, during which one, two and three times of quenching were performed, respectively. The characteristics and properties of the sensors developed with different quenching times were examined extensively, which include surface morphology, section structure, porosity distribution, as well as the linear range of E-pH response, pH response rate, and the long time stability, etc. It is found that the sensors quenched for three times appear to show better performance. Electrochemical impedance spectra (EIS) of the iridium oxide electrodes were investigated in pH buffering electrolyte to analyze the pH response mechanism of the electrode.
Surface-Enhanced Raman Scattering on Ordered Metal Nanodot Array Obtained Using Anodic Porous Alumina
Authors: Kondo Toshiaki , Nishio Kazuyuki , Masuda Hideki
Published: March 2013

The fabrication of an ordered array of Au nanodots using anodic porous alumina as an evaporation mask, and its application to a substrate for the measurement of surface-enhanced Raman scattering (SERS) were studied. One of the advantageous points of using anodic porous alumina as a template to fabricate nanostructures is that the size, shape and arrangement of the obtained nanostructures can be controlled by changing the geometrical structures of the porous alumina. Au nanodot arrays were obtained by thermal evaporation method. The SERS signals of pyridine molecules adsorbed on the nanodots were detected. The intensity of the SERS signals was strongly dependent on the arrangement of the nanodots. The enhancement factor of the intensity of the incident light on Au nanodots was analyzed by numerical calculations based on finite-difference time-domain (FDTD) method. The obtained SERS substrates are expected to be used for Raman spectra measurement with high sensitivity.
Adaptive Chemical Sampling Device Inspired by Crayfish
Authors: Takemura Ryuichi , Takahashi Kenji , Makishita Tomomi , Ishida Hiroshi
Published: March 2013

Crayfish are known to generate water jets by waving their special appendages with a fan-like shape. The generated jets entrain surrounding water, and thus inflow converging toward their olfactory organs is induced. Therefore, the jets are considered to help crayfish collect water samples to search for the smell of a prey. Although crayfish are also known to be able to change the direction of the jet discharge, its implication in olfactory search has not been well understood. To investigate this issue, we have developed a chemical sampling device equipped with a jet discharger and electrochemical sensors. Results of computational fluid dynamics analyses and chemical detection experiments are presented to show that the angular range of water-sample collection can be adjusted by changing the jet discharge directions. The results suggest that the olfactory search efficiency can be improved by narrowing down the angular sample collection range as the search progress.
NO2 Sensing Properties of Porous In2O3-Based Powders Prepared by Utilizing Ultrasonic-Spray Pyrolysis Employing PMMA Microsphere Templates: Effects of the Size of the PMMA Microspheres on Their Gas-Sensing Properties
Authors: Fujii Eriko , Hyodo Takeo , Matsuo Katsuhide , Shimizu Y.
Published: March 2013

PMMA microspheres were synthesized in distilled water by ultrasonic-assisted emulsion polymerization. The average particle size of PMMA microspheres was dependent marktedly on the kind of surfactant used. Porous (pr-) In2O3 powders were prepared by ultrasonic-spray pyrolysis of In(NO3)3 aqueous solution containing the PMMA microspheres synthesized. The NO2 response of pr-In2O3 was much larger than that of conventional In2O3 powder prepared by the similar technique employing PMMA-free In(NO3)3 aqueous solution. The introduction of controlled macroporous structure into the powder of the sensor material was found to be effective for improving NO2 response properties.
Sensing Characteristics of a Fiber Bragg Grating Hydrogen Gas Sensor Using Sol-Gel Derived Pt/WO3 Film
Authors: Okazaki Shinji , Maru Yusuke , Mizutani Tadahito
Published: March 2013

A fiber-optic hydrogen gas sensor based on a shift of Bragg wavelength induced by reaction heat and strain was developed. Platinum-supported tungsten trioxide (Pt/WO3) film which was utilized as hydrogen sensitive material was derived by sol-gel method. In this study, two types of the sensor structures were fabricated and evaluated. The sensor device where fiber Bragg grating (FBG) was fixed on the quartz glass substrate coated with the Pt/WO3 film using adhesive tape showed good sensitivity. It was found that both reduction of WO3 and oxidation of tungsten bronze were exothermic reaction. The heat generated by the oxidation process was considerably larger than that of reduction. The response behavior of the other type FBG sensing device directly coated with Pt/WO3 film was complicated. It was suggested that there seemed to be competitive response mechanisms related to generation of reaction heat and strain in reduction and oxidation process of sensing film.
Zirconia-Based Electrochemical Oxygen Sensor for Accurately Determining Water Vapor Concentration
Authors: Soltis Richard E
Published: March 2013

By varying the control voltages of commercially available zirconia-based automotive exhaust gas oxygen sensors, other oxygen-containing molecules such as H2O and CO2 can be measured. Typical water concentration sensors that measure relative humidity via swelling of certain polymers have a narrow temperature range of operation (typically < 120{degree sign}C) and limited accuracy of about {plus minus} 0.4% absolute. Initial measurements with modified zirconia oxygen sensors, both in the laboratory and on engine dynamometers, have shown that water vapor concentration in a gas stream can be measured accurately to {plus minus} 0.1% over the range from 0-20 vol% H2O at temperatures up to 800{degree sign}C.
Application of Commercial Manufacturing Methods to Mixed-Potential NOx Sensors
Authors: Kreller Cortney R. , Sekhar Praveen K. , Li Wenxia , Palanisamy Ponnusamy , Brosha Eric L. , Mukundan Rangachary , Garzon Fernando H.
Published: March 2013

Commercial manufacturing methods have been used to fabricate a planar, self-heated, tape-cast, mixed-potential NOx sensor for application in vehicle on-board emission control systems. The device consists of dense La0.8Sr0.2CrO3 (LSCrO) and Pt electrodes and a porous YSZ electrolyte on one side of a dense ceramic substrate and a Pt-heater with independent leads on the backside of the substrate. These planar mixed-potential sensors are capable of selectively detecting ppm levels of NOx when operated at a positive bias. Additionally, the device has yielded stable performance under months of testing as a result of the stable morphology of the electrode/electrolyte/gas phase interface.
Research on Filter Materials for LP Gas Sensors
Authors: Sai Masakazu , Shinnishi Kazuya , Kaneyasu Kazunari , Suzuki Toshiya , Takeuchi Masato
Published: March 2013

It is well known that semiconductor gas sensor characteristics may change when exposed to siloxane vapor. In this study, we examined filter materials to improve the siloxane durability of the LP gas sensor. Adsorption isotherms of octamethylcyclotetra-siloxane (D4) at 298 K were measured for each filter materials. As a result, γ-Al2O3 showed high performance in adsorption amount. However, the sensor with mixed filter materials of MPR-PEG (Mordenite zeolite modified with polyethylene glycol) and γ-Al2O3 was more stable after the D4 durability test than the sensors with the single filter materials. The γ-Al2O3 mixed with MOR-PEG maintains capacity for D4.
Self-Assembled Monolayers of Oligonucleotides as Receptor Layers for Mercury Ion Sensor
Authors: Górski Lukasz , Ziółkowski Robert , Malinowska Elzbieta
Published: March 2013

The feasibility of using gold electrodes modified with short-chain, thymine-rich, ss-DNA oligonucleotides for determination of mercury cation is examined. The methylene blue was used as a redox marker for analytical signal generation. Biosensor response was based on the difference in electrochemical signal before and after subjecting it to sample containing Hg2+ ion. The lower detection limit of 3 nmol L-1 for Hg2+ was observed, together with good selectivity against common metal cations.
Layer-by-Layer Catalytic Interface for Electrochemical Detection of Multiple Substrates Featuring Bio-Functionalized Carbon Nanotubes
Authors: Kirsch Jeffrey S. , Yang X. , Simonian Aleksandr
Published: March 2013

Built upon previously gained knowledge, a novel, layer by layer assembled carbon nanotube sensor for detection of two analytes is discussed. The main idea is to functionalize the carbon nanotubes with different enzymes and bio-polymers to build a multi-functional series of interfaces, which are sensitive to their respective substrates. Organophosphorus hydrolase and glucose oxidase should be separately, covalently immobilized onto multi-walled carbon nanotubes (MWNT-OPH and MWNT-GOx) for catalytic hydrolysis of the model organophosphate, paraoxon (PX) and catalytic oxidation of β-D-glucose. The catalytic response of the different layers was characterized by amperometry with redox mediator. While the sensor to simultaneously detect both glucose and paraoxon is not inherently practical, the experiment shows the possibility for co-interfacing multiple enzymes on the same platform. This may be very important to allow for the detection of several substrates, through the use of numerous biocatalysts on separate layers. Additionally, this approach might be applied for systems where several biocatalysts are assembled to work in a consecutive mode and the product of previous reaction might be a substrate for the next one.
Superoxide Anion Radical Sensor Using GC Electrode Modified with Heparin/PEDOT and Polymerized Iron Porphyrin
Authors: Matsuoka Ryo , Kondo Takeshi , Yuasa Makoto
Published: March 2013

Blood coagulation on the electrode surface is a serious problem for a superoxide anion radical (O2−∙) sensor because it causes deterioration of the current signal especially in vivo. In order to solve this problem, we have developed iron porphyrin-based O2−∙ sensors immobilizing heparin, which is an anti-thrombotic compound, on the surface. In the present study, we immobilized heparin with a polyethylenedioxythiophene (PEDOT) matrix on poly[iron tetrakis(3-thienyl)porphyrin]-modified glassy carbon (GC) electrode, and the stability of the modified sensor to blood coagulation was investigated. The PEDOT matrix was found to be more effective for stable electrochemical detection of O2−∙ after immersion in a fibrinogen/thrombin solution for two weeks, while serious electrode fouling due to blood clot formation was occurred at a sensor using a polypyrrole matrix after immersion in the solution for one week.
High Sensitive Amperometric Detection of Glucose Using Conductive DLC Electrode in Higher Potential Region
Authors: Honda Kensuke , Nakahara Akira , Naragino Hiroshi , Yoshinaga Kohsuke
Published: March 2013

The possibility of a high sensitive amperometric detection of glucose using electrochemically-generated hydroxyl radicals at N-doped DLC was examined. Flow injection analytical system using N-doped DLC as an electrode of electrochemical detector showed higher performance of glucose detection in a potential region of oxygen evolution (>3.6 V vs. Ag|AgCl). Linear dynamic range was 5 orders of magnitude (1 μM to 10 mM) and theoretical detection limit (S/N = 3) was 1.37 mM at 3.6 V vs. Ag|AgCl. In addition to glucose, linear relations between values of response current and of sample concentration were observed in molecules easily oxidized by OH radicals (ascorbic acid, 2-propanol, ethyl acetate and ethyl acetoacetate). The oxidation of glucose mediated by OH radicals generated at N-doped DLC in higher potential region is included in the mechanism of amperometric glucose detection at N-doped DLC.
Electrochemical Immunosensor for Diagnostic of Parasitical Human Diseases
Authors: Erdmann Cristiane Andreia , Inaba Juliana , Viana Adriano Golçalves , Pessoa Christiana Andrade , Wohnrath Karen , Garcia Jarem Raul
Published: March 2013

In this paper the preparation and electrochemical characterization of an immunosensor for Chagas disease is described. The results obtained indicating the possibility of the modification of ITO surface by formation of a LbL film constructed by the intercalation of PVS as polyanion and AgNP-SiPy+ as polycation. The LbL films were then modified by incorporation of Chagas ATG on their surface. These modified LbL films showed a pronounced impedance change when in the presence of the Chagas ATB indicating that this kind of film could be used in a device for diagnosis of Chagas disease.
Preparation of Fine Implantable Needle Type Biosensors for Blood Vessel Glucose Monitoring
Authors: Edagawa Kazuaki , Yasuzawa Mikito
Published: March 2013

Fine needle type glucose sensors with variety of outer membrane were prepared and their glucose sensor properties were evaluated by in vitro measurement in phosphate buffer solution and horse serum, and in vivo measurement using the veins of rats and rabbits. Outer membrane materials of polyglutamic acid (PGA) and heparin, which provide hydrophilic surface were introduced in addition to polyurethane(PU)/polydimethylsiloxane (PDMS) composite outer membrane. Glucose sensors with PU/PDMS outer and PGA extra-outer film showed glucose response on the day of implantation, while clear response was not obtained after 18 hours of implantation due to the adsorption of the thrombus on the sensor surface. On the other hand, the sensor with heparin outer membrane provided satisfactory glucose response also in the second day.
Tunable Young's Modulus in Carbon MEMS Using Graphene-Based Stiffeners
Authors: Washburn Cody M , Lambert Timothy N. , Blecke Jill , Davis Danae , Finnegan Patrick S. , Hance Brad G. , Wheeler David R. , Beechem Thomas E. , Alam Todd M. , Brumbach Michael T. , Strong Jennifer M.
Published: March 2013

Carbon composite micro-electromechanical systems (C-MEMS) incorporating 2 wt.% graphene stiffeners show a 65% increase in Young's modulus and 11% increase in conductivity. An improved reduced graphene oxide (iRGO), is blended into pyrolytic carbon beams prepared for resonant frequency testing. Designed around a 10:1 (length: width) aspect ratio, the linearity of wt.% iRGO in the cantilevers as a function of resonant frequencies is evaluated. The collection of the 1st through 3rd bending modes using laser doppler velocimetery (LDV) of the graphene filled cantilevers shows an increase in frequency response with nanomaterial loading (wt.%). A model was developed using the 3-bending modes and correlated with cross sectional geometry and density to extract a Young's modulus.
Residue-Free Dry Etching of Polymer Sacrificial Layer for Microelectromechanical-System Device Fabrication
Authors: Takagahara Kazuhiko , Ono Kazuyoshi , Kuwabara Kei , Sakata Tomomi , Ishii Hiromu , Sato Yasuhiro , Jin Yoshito
Published: March 2013

Residue-free dry etching of a photosensitive-polymer sacrificial layer using O2/CF4/CO-plasma exposure is described for the fabrication of microelectromechanical-system (MEMS) devices. Energy dispersive X-ray spectroscopy reveals that O2/CF4/CO-plasma exposure removes polymer sacrificial layers without leaving residue and severely damaging Au structures. Since the O2/CF4/CO-plasma exposure hardly damages Au structures, this process is applicable for the removal of sacrificial layers for MEMS with Au structures.
Hydrodynamic Cell Enrichment in Double Spiral Microfluidic Channels
Authors: Sun Jiashu , Li Mengmeng , Liu Chao , Hu Guoqing , Jiang Xingyu
Published: March 2013

Rapid cell separation and enrichment has attracted significant attention because of its important applications in cell biology studies and biomedical diagnostics. we have developed a compact microfluidic platform, composed of 6-loop double spiral microchannels, to separate cancer cells from blood cells. The curved geometry induces a Dean drag force acting on cells to compete with the inertial lift, resulting in different equilibrium positions for different sized cells. The separation chip is characterized with the mixture of 4T1 cells and the murine blood cells at different flow rates, with decent separation and enrichment efficiency.
Nano/Micro Patterned Phononic Crystals
Authors: Kim Bongsang , Nguyen Janet , Reinke Charles , Ziaei-Moayyed Maryam , El-Kady Ihab , Goettler Drew , Su Mehmet , Leseman Zayd C. , Olsson Roy H.
Published: March 2013

Recently, with the application of micro/nano machining technologies, there have been immense strides in the research of phononic crystals. This paper reviews basics of micro/nano fabricated 2D phononic crystals, and discusses their promising applications, particularly for RF signal processing and thermal conductivity manipulation with several examples of Sandia National Laboratories.
Photothermal Cantilever Deflection Spectroscopy
Authors: Kim Seonghwan , Lee Dongkyu , Thundat Rachel , Bagheri Mehrdad , Jeon Samgmin , Thundat Thomas
Published: March 2013

A real-time technique that does not rely on chemical interfaces or biological receptors for molecular identification of picogram quantities of biomaterials such as DNA molecules in a high throughput fashion is described. This technique combines the extremely high sensitivity of microfabricated bi-material cantilever beams with the high selectivity of mid infrared (IR) spectroscopy to nanomechanically transduce the photon absorption-induced temperature variations of the molecules. Picogram amounts of target molecules were first adsorbed on the cantilever without using any receptors. Illuminating a bi-material cantilever sequentially with a mid-IR radiation results in photon absorption by the molecule at a certain wavelength, which results in a small temperature variation, and the resultant deflection of the bi-material cantilever. A plot of cantilever deflection as a function of an illuminating wavelength closely follows the IR absorption spectrum of the target molecules. We have used this technique to rapidly identify different DNA strands.
Manipulation of Micro Condensed Matter by Direct Peeling Method by Using Atomic Force Microscope Tip
Authors: Kawai Akira
Published: March 2013

Understanding manipulation properties of polymer nanoscale pattern is of crucial importance for development of not only MEMS/NEMS devices but other functional devices in the nanometer scale. Quantitative analysis of peel and manipulate properties of an ArF dot resist pattern ranging from 141 to 405 nm diameter and 360 nm height is demonstrated experimentally. By directly applying a certain load to top corner of resist pattern with a micro cantilever tip, a resist dot pattern can be peeled easily from a substrate accompanying slight residue formation. The load required for pattern peel decreases with decreasing the pattern diameter. In combination with the analysis of internal stress distribution in the resist pattern, an optimum condition for successful manipulation condition can be obtained. The rearrangement of 141nm diameter pattern can be demonstrated by the tip manipulation technique.
Effects of Adsorbate Surface Diffusion in Focused Electron-Beam-Induced-Deposition
Authors: Szkudlarek Aleksandra , Gabureac Mihai , Utke Ivo
Published: March 2013

The time-dependent continuum model is applied to simulate a growth of structures with a non-rotational symmetry. The surface diffusion of adsorbates, depending on the beam parameters and the deposit size, may lead to the different growth rate along deposited structures. Here, a few conventional patterning strategies have been studied: spiral inwards, spiral outwards and zigzag.
Electroplating of Micropatterned Nickel Phase Gratings for X-ray Phase Contrast Tomography
Authors: Amberger Maximilian , Bade Klaus , Meiser Jan , Kunka Danays , Mohr Juergen
Published: March 2013

We report on a new approach of monitoring Nickel-Sulfamate based electroplating baths to obtain a more precise control of the height of x-ray phase contrast gratings. The influence of the Ti/TiOx film substrates on electroplating start and behavior is investigated. A four phase electroplating sequence was recorded and utilized to adaptively control the height of electroplated samples.
Impact of Donor Dopant on Acceptor Solubility in TlBr
Authors: Bishop Sean R. , Tuller Harry L.
Published: March 2013

The predicted dependence of TlBr room temperature ionic conductivity on divalent donor and acceptor dopant concentration is presented, taking into account acceptor dopant exsolution and dopant-defect association. Donor-acceptor compensation is found to play a key role in determining the ultimate room temperature conductivity with donors increasing the solubility of acceptors from 0.04 ppm (0 donor) to 0.84 ppm (1 ppm donor) to 8.4 ppm (10 ppm donor).
Microfabricated Systems to Measure Marine Variables
Authors: Aravamudhan Shyam , Bhansali Shekhar
Published: March 2013

The goal of this paper is to provide a basis for MEMS marine-specific sensors and their associated harsh environmental packaging. Specifically, this paper will discuss our efforts in the development of two microfabricated systems to measure marine variables - (a) MEMS-based electrochemical systems to measure marine nutrients and (b) reinforced MEMS pressure sensor to measure spatial depths. The electrochemical detection-on-chip module was fabricated using assembled polypyrrole (PPy) nanowires as the sensing element. The measurement of nitrate ions in a flow through environment is presented here. For the depth measurements, we developed the double diaphragm or reinforced configuration to measure pressure/depth at both higher sensitivity (27% higher) and wider linear operating range (> 400 psi, from combination of inner and outer diaphragms) compared to the conventional single diaphragm design.
Micropatternable, Electrically Conducting Polyaniline Photoresist Blends for MEMS Applications
Authors: Patel Chintan V. , Khosla A. , Kassegne Sam
Published: March 2013

We present preparation and electrical characterization of Polyaniline (PANi) SU8 micropatternable photoresist blend for MEMS applications. The blend was prepared by shear mixing of PANi and SU8-2010 at an rpm of 1000 for 15 hours. The composite was spin coated on a silicon wafer at an 850 rpm in order to achieve a thickness of 50µm, followed by soft baking at 70 {degree sign}C for 35 minutes and cooling to room temperature. The desired structures were patterned using masked UV exposure for 60 seconds. Full cross linking of PANi SU-8 blend was achieved by a post-exposure bake at a temperature of 90{degree sign}C for 25 minutes followed by cooling to room temperature. The desired electrode structures and trace lines were then developed in SU-8 developer (Microchem{trade mark}) for 10 minutes by manual agitation. The fabricated structures were analyzed under SEM and Electron Dispersion X-ray Spectroscopy (EDS) demonstrating that an electrically conductive path is formed by PANI in SU-8 polymer matrix. It was also observed that resistivity of 4×103 Ω-m is achieved at 8.6 weight percentage of PANi in SU-8 polymer matrix.
Ion Bombardment during Plasma-Assisted Atomic Layer Deposition
Authors: Profijt Harald Benjamin , Kessels W.M.M.
Published: March 2013

The presence and influence of ions in several reactor configurations used for plasma-assisted ALD are discussed. It is shown that the ion energies are often moderate or even negligible in direct plasma and remote plasma ALD reactors under processing conditions typically employed. Plasma-induced damage by ion-bombardment is therefore not a major issue during most processes. It has furthermore been demonstrated that ion energies can be enhanced using substrate biasing, which can be used to tailor the material properties as demonstrated for several metal-oxides.
Crystallization Study by Transmission Electron Microscopy of SrTiO3 Thin Films Prepared by Plasma-Assisted ALD
Authors: Longo Valentino , Roozeboom F. , Kessels W.M.M. , Verheijen Marcel A.
Published: March 2013

The crystallization behavior of thin strontium titanate (SrTiO3, STO) films with ~15 nm thickness was studied by Transmission Electron Microscopy (TEM). Amorphous STO films with [Sr]/([Sr]+[Ti]) ratio ranging from 0.51 to 0.65 were deposited at 350 {degree sign}C by plasma-assisted ALD and subsequently treated by rapid thermal annealing for crystallization. Different temperatures and annealing durations were employed to fully characterize the crystallization process. TEM analysis evidenced the influence of the STO composition and of the thermal budget applied on the grain size, cracks and void formation. In particular, Sr-rich layers ([Sr]/([Sr]+[Ti] {greater than or equal to} 0.6) showed a finer crystalline structure which was imputed to a higher nucleation probability at the onset of the crystallization process. By tuning the STO composition and the thermal budget of the annealing step it was demonstrated that it is possible to control the microstructure of the crystallized STO layers.
Plasma Surface Modification of Blown Polyethylene Films for Uniform Atomic Layer Deposition of Al2O3
Authors: Lee Gyeong Beom , Son Kyung Sik , Park Suk Won , Shim Joon Hyung , Choi Byoung-Ho
Published: March 2013

As polyethylene has unique physical characteristics such as low surface energy, low crystallization temperature, lack of polar groups, complicated lamellar structures, susceptibility to thermal degradation, and so on, most conventional coating techniques are not suitable for it. Atomic layer deposition (ALD) has many benefits over conventional coating techniques, and it can be a good candidate as a coating technique for polyethylene. In this study, a low-temperature ALD technique for depositing layers of Al2O3 on blown, high-density polyethylene (HDPE) films was investigated. The effect of plasma surface modification on the effectiveness of the ALD technique in Al2O3 layer formation was also studied.
Room-Temperature ALD of Metal Oxide Thin Films by Energy-Enhanced ALD
Authors: Potts Stephen Ernest , Profijt Harald Benjamin , Roelofs Robin , Kessels W.M.M.
Published: March 2013

Room temperature ALD (RT-ALD) processes are of interest for applications using temperature-sensitive substrates, yet they are not so commonly reported. The challenges associated with RT-ALD arise when surface groups are not sufficiently reactive toward incoming precursors and vice versa, the precursors are not sufficiently volatile, and purge times become impractically long. These challenges can be overcome using energy-enhanced ALD. We demonstrate here viable energy-enhanced RT-ALD (25 °C) processes for Al2O3 and SiO2 from trimethylaluminium (TMA) and bis(diethylamino)silane (SAM.24) precursors, enabled using an O2 plasma or ozone as co-reactants. Saturated ALD growth was obtained at room temperature for the TMA/O2 plasma, TMA/ozone, and SAM.24/O2 plasma processes, whereas the SAM.24/ozone RT-ALD process gave no growth. Using these results, the essential and desirable criteria that are necessary to obtain a viable RT-ALD process are discussed.
Electrocatalytic Activity of Pt Grown by ALD on Carbon Nanotubes for Si-Based DMFC Applications
Authors: Johansson Anne-Charlotte , Dalslet Bjarke T. , Yang Ren Bin , Haugshøj Kenneth B. , Mølgaard Mathias J. G. , Christiansen Kim , H. Christensen Leif , V. Thomsen Erik
Published: March 2013

We present an anode design for silicon-based direct methanol fuel cell (DMFC) applications. Platinum was deposited conformally by atomic layer deposition (ALD) onto vertically aligned, nitrogen-doped multi-walled carbon nanotubes (MWCNTs) grown on porous silicon. The deposition was carried out in a top-flow ALD reactor at 250{degree sign}C, using MeCpPtMe3 and O2 as precursors. The anode was tested for the methanol oxidation reaction (MOR) in a three-electrode electrochemical set-up and it showed improved catalytic activity compared to a reference sample of Pt deposited on flat Si. It is demonstrated that ALD could be a MEMS compatible deposition technique for Si-based fuel cell applications.
High Performance Core-Shell Nanowire Array Devices Prepared by Atomic Layer Deposition
Authors: Kim Hyungjun , Ko Kyungyong , Kang Hyemin
Published: March 2013

Atomic layer deposition (ALD) is a promising nanomaterial synthesis technique due to its excellent confomality over complicated nanostructure. We fabricated ALD semiconducting oxide/semiconductor core-shell nanowire array and characterized the device performances as a photodiode. Si nanowires array with about 100~300 nm diameter were prepared using electroless etching technique. Nitrogen doped ALD ZnO was carried out using diethylzinc (DEZ) and diluted NH4OH various growth temperature. We measured responsivity and external quantum efficiency of the fabricated device as a function of wavelength of incident light and compared with thin film based photodiode. For NW array device, the photocurrent density and responsivity were significantly enhanced compared to thin film based device. Also, by combining self-assembly process, well ordered core-shell ZnO/Si nanowire arrays were prepared. The device performance made of ordered core-shell NW arrays was significantly enhanced. In addition, ZnO homojunction NW photodiode as well as ALD TiO2 outer shell NW photodiodes were fabricated and their device characterizations were compared to the planar type device.
Impact of Direct Plasma Densification on Resistivity and Conformality of PEALD Tantalum Nitride
Authors: van der Straten O. , Zhang X. , Penny C. , Maniscalco J. , Chiang S. , Ren J. , Ma P.
Published: March 2013

A novel plasma enhanced atomic layer deposition (PEALD) process was demonstrated for tantalum nitride (TaN) based on the reduction of pentakis(dimethylamino)tantalum (PDMAT). High-power, direct plasma densification steps were incorporated into each PEALD growth cycle, resulting in ion bombardment of the TaN surface during growth. These densification steps enabled the deposition of low-resistivity, high-density TaN. Physical film densification by ion bombardment was confirmed from the observed thickness reduction of TaN deposited by PEALD with densification steps compared to PEALD without densification steps, for an equivalent number of PEALD cycles. In terms of PEALD TaN resistivity, ion-bombardment induced densification resulted in a reduction by an order of magnitude, from ~4000 μΩcm to ~400 μΩcm. In patterned trench structures, ion bombardment can achieve densification of PEALD TaN at the trench bottom while sidewall surfaces appear to show a less significant reduction in film thickness.
Emerging Research Devices and Architectures for More-Than-Moore Applications
Authors: Chen An
Published: March 2013

With CMOS scaling facing increasingly challenging technological and economical barriers, many novel devices, materials, and architectures have emerge as potential post-CMOS solutions. Although many emerging research devices are not better than CMOS for general-purpose computing, they may provide novel functionalities promising for More-than-Moore (MtM) applications. This paper reviews the emerging devices explored by the nanoelectronics research community. A particularly promising MtM application of some of these emerging devices is RF electronics. Broad range of MtM applications and the challenges of MtM technology roadmap are discussed.
Multi-Physics Equivalent Circuit Model for MEMS Sensors and Actuators
Authors: Konishi Toshifumi , Machida Katsuyuki , Masu Kazuya , Toshiyoshi Hiroshi
Published: March 2013

Multi-physics simulation is becoming an indispensable technique for integrated MEMS (micro electro mechanical systems) to comprehend the system level behavior including electronics, mechanics, and/or other physics domain such as optics. We have newly developed a single platform simulation technique for MEMS by using a compact model solver for the mechanical equation-of-motion implemented as an analog computation circuit on an electrical circuit simulator such as Qucs, LTspice and Cadence Virtuoso. In this talk, we review the conventional methods to develop an equivalent circuit model for MEMS and report our own simple and useful technique to create a compact model for electrostatic micro actuators and sensors by translating the algebraic analytical model into an equivalent circuit model based on the non-linear independent current source.
ThruChip Interface for Heterogeneous Chip Stacking
Authors: Kuroda Tadahiro
Published: March 2013

This paper presents a wireless inter-chip link using inductive coupling, namely ThruChip Interface (TCI). TCI is a digital CMOS circuit solution in a standard CMOS technology. It is much less expensive than TSV (Through Silicon Via) but bears comparison in performance. Delay time and energy dissipation will scale down by scaling device size and chip thickness. As the inductive coupling enables interface among chips under different supply voltages, TCI is suitable for heterogeneous integration. A 90nm 8-core processor under 1.0V power supply and two 65nm SRAM's under 1.2V power supply are stacked and AC-coupled by TCI at 19.2Gb/s. Power dissipation and area efficiency of the link is 1pJ/b and 0.15mm2/Gbps respectively, which is 1/30 and 1/3 in comparison with the conventional DDR2 interface.
Measurement Science for "More-Than-Moore" Technology Reliability Assessments
Authors: Okoro Chukwudi A. , Ahn Jung-Joon , Kelso Meagan , Kabos Pavel , Kopanski Joseph J. , Obeng Yaw S.
Published: March 2013

In this paper, we will present an overview of metrology issues and some of the techniques currently under development in our group at NIST, aimed at understanding some of the potential performance limiting issues in such highly integrated systems. We will discuss our attempts to identify and characterize the various types of defects and relate them to where and why they form, without interrupting the responsible phenomena.
Improving Ion/Ioff In Bilayer Graphene Transistors by Molecular Functionalization
Authors: Nourbakhsh Amirhasan , Cantoro Mirco , Klekachev Alexander V , Asselberghs Inge , Heyns Marc M. , Sels Bert F , De Gendt Stefan
Published: March 2013

We propose a bilayer graphene (BLG) device concept that allows to overcome the problem of zero bandgap in pristine BLG by all-organic asymmetrical functionalization. The BLG is sandwiched between a top p-dopant layer (F4TCNQ) and a bottom n-dopant layer (APTES), establishing a transverse electric field needed for bandgap opening. We demonstrate the occurrence of n- and p-type doping by studying the separate effects of the interaction of single-layer graphene (SLG) with the two molecular species. We confirm the occurrence of doping by electrical measurements performed on functionalized SLG samples integrated in a back-gated SLG-FET structure. We measure excess charge concentrations of n=-1.3×10^13 cm-2 and n=+1.2×10^13 cm-2 for respectively n- and p-type doping. The results of DFT calculations further corroborate our experimental results and confirm that the BLG device structure proposed could pave the way for the use of graphene in microelectronics.
The Influence of Landscape and Microhabitat on the Diversity of Large- and Medium-Sized Mammals in Atlantic Forest Remnants in a Matrix of Agroecosystem and Silviculture
Authors: Bogoni Juliano André , Bogoni Talita Carina , Graipel Maurício Eduardo , Marinho Jorge Reppold
Published: March 2013

Fragmentation and destruction of a habitat are strongly relevant aspects to determine the richness and the dynamics of the mammals in ecosystems. This study, developed from October, 2010 to July, 2011 in three Atlantic Forest remnants in Ipumirim, SC, Brazil, aims at identifying the diversity of large- and medium-sized nonflying mammals and verifying associations of the patterns obtained with features of the researched areas. The approximate measurement of the inventoried areas is 51 ha. The data collection of the mammal fauna was obtained through direct registers, with the use of a photographical trap, and indirect records through the search of material that indicated the presence of species. The total amount of species studied was 13, pertaining to nine families: Canidae (1), Cebidae (1), Dasyproctidae (1), Dasypodidae (2), Didelphidae (2), Felidae (2), Mustelidae (2), and Procyonidae (2). In addition, landscape data was obtained through the development of a chorological matrix of the areas and the data about the microhabitats. From these data, 20 models for analysis were stipulated and this selection was determined with the corrected Akaike Information Criterion (AICc). The aspect of greater influence on the magnitude of the obtained data was the degree of human occupation in the landscape.