Engineering Commons^™

Progress Towards Terahertz Acoustic Phonon Generation In Doping Superlattices, Thomas E. Wilson

Thomas E. Wilson

Progress is described in experiments to generate coherent terahertz acoustic phonons in silicon doping superlattices by the resonant absorption of nanosecond-pulsed far-infrared laser radiation. Future experiments are proposed that would use the superlattice as a transducer in a terahertz cryogenic acoustic reflection microscope with sub-nanometer resolution.

Exploring Public Values Implications Of The I-Corps Program, Jan Youtie, Philip Shapira

Philip Shapira

Polarization At Metal--Biomolecular Interfaces In Solution, Hendrik Heinz, Kshitij Jha, Jutta Luettmer-Strathmann, Barry Farmer, Rajesh Naik

Jutta Luettmer-Strathmann

Metal surfaces in contact with water, surfactants and biopolymers experience attractive polarization owing to induced charges. This fundamental physical interaction complements stronger epitaxial and covalent surface interactions and remains difficult to measure experimentally. We present a first step to quantify polarization on even gold (Au) surfaces in contact with water and with aqueous solutions of peptides of different charge state (A3 and Flg-Na3) by molecular dynamics simulation in all-atomic resolution and a posteriori computation of the image potential. Attractive polarization scales with the magnitude of atomic charges and with the length of multi-poles in the aqueous phase such as the …

Uv-Absorption And Silica/Titania Colloids Using A Core--Shell Approach, Liang Zhou, Hendrik Heinz, Mark Soucek, Elvin Aleman, David Modarelli

David A. Modarelli

Metal-oxo-colloids have been prepared using tetraethoxysilane (TEOS) oligomers with titanium tetra-i-propoxide (TIP) or titanium (di-i-propoxide) bis(acetylacetonate) (TIA) precursors. Transmission electron microscopy (TEM), FTIR, UV-Vis, and photoluminescence spectroscopy were used to investigate the composition, the size, and optical properties of the Si/Ti core–shell colloids. The presence of hetero-bonded silicate structure (Si–O–Ti) was indicated by FTIR spectroscopy. The size of Si/TIP system ranged from 55 to 120 nm and Si/TIA system ranged from 220 to 250 nm. The TEM data indicated that the size of colloids can be controlled by the TIP or TIA content. The Si/Ti system …

High-Throughput Screening Of Shape Memory Alloy Thin-Film Spreads Using Nanoindentation, Arpit Dwivedi, Thomas Wyrobek, Oden Warren, Jason Hattrick-Simpers, Olubenga Famodu, Ichiro Takeuchi

Jason R. Hattrick-Simpers

We have demonstrated the utility of nanoindentation as a rapid characterization tool for mapping shape memoryalloy compositions in combinatorial thin-film libraries. Nanoindentation was performed on Ni–Mn–Al ternary composition spreads. The indentation hardness and the reduced elastic modulus were mapped across a large fraction of the ternary phase diagram. The large shape memoryalloy composition region, located around the Heusler composition (Ni2MnAl), was found to display significant departure in these mechanical properties from the rest of the composition spread. In particular, the modulus and the hardness values are lower for the martensite region than those of the rest of the phase diagram.

The Materials Super Highway: Integrating High-Throughput Experimentation Into Mapping The Catalysis Materials Genome, Jason Hattrick-Simpers, Cun Wen, Jochen Lauterbach

Jason R. Hattrick-Simpers

No abstract provided.

Too Enthusiastic To Care For Safety: Present Status And Recent Developments Of Nanosafety In Asean Countries

Faculty of Engineering University of Malaya

Nanotechnology has the prospect to vibrate the imagination of human being and has the ability to be used in almost every sector of human need. With its limitless potentials, there are many environmental, health and safety related concerns due to extremely ambivalent effects of nanoparticles. Studies revealed that nanoparticles can enter the human body through the lungs, intestinal tract, and skin. Therefore, the researchers and workers who handle nanoparticles and nanomaterials can theoretically and primarily be affected, whereas on the consumers this will have secondary effects. This paper aims at sharing and evaluating the investment scenario, present status and recent …

Is There A Relationship Between Research Sponsorship And Publication Impact? An Analysis Of Funding Acknowledgments In Nanotechnology Papers, Jue Wang, Philip Shapira

Philip Shapira

This study analyzes funding acknowledgments in scientific papers to investigate relationships between research sponsorship and publication impacts. We identify acknowledgments to research sponsors for nanotechnology papers published in the Web of Science during a one-year sample period. We examine the citations accrued by these papers and the journal impact factors of their publication titles. The results show that publications from grant sponsored research exhibit higher impacts in terms of both journal ranking and citation counts than research that is not grant sponsored. We discuss the method and models used, and the insights provided by this approach as well as it …

Social Science Contributions Compared In Synthetic Biology And Nanotechnology, Philip Shapira, Jan Youtie, Yin Li

Philip Shapira

With growing attention to societal issues and implications of synthetic biology, we investigate sources of social science publication knowledge in synthetic biology and probe what might be learned by comparison with earlier rounds of social science research in nanotechnology. “Social science” research is broadly defined to include publications in conventional social science as well as humanities, law, ethics, business, and policy fields. We examine the knowledge clusters underpinning social science publications in nanotechnology and synthetic biology using a methodology based on the analysis of cited references. Our analysis finds that social science research in synthetic biology already has traction and …

Nanotechnology Companies In The United States: A Web-Based Content Analysis Of Companies And Products For Poverty Alleviation, Thomas Woodson

Thomas Woodson

This study analyzes the goals, nanotechnology experience, corporate social responsibility and products of 50 USA-based companies working with nanotechnology to see if they are developing products that help low-income populations. Out of the top 50 R&D companies that publish and patent nanotechnology research in agri-food, energy and water sectors, 18 of them do not mention nanotechnology on their websites. The other 32 companies discuss nanotechnology in varying degrees. However, only two of the companies relate their nanotechnology R&D to poverty alleviation. Even though few companies refer to poverty alleviation, 30 firms of the sample have some type of corporate social …

Integration Of Biosensors Based On Microfluidic: A Review

Faculty of Engineering University of Malaya

Purpose - Biotechnology is closely associated to microfluidics. During the last decade, designs of microfluidic devices such as geometries and scales have been modified and improved according to the applications for better performance. Numerous sensor technologies existing in the industry has potential use for clinical applications. Fabrication techniques of microfluidics initially rooted from the electromechanical systems (EMS) technology. Design/methodology/approach - In this review, we emphasized on the most available manufacture approaches to fabricate microchannels, their applications and the properties which make them unique components in biological studies. Findings - Major fundamental and technological advances demonstrate the enhancing of capabilities and …

Criterion For An Oscillatory Charged Jet During The Bubble Spinning Process, Ji-Huan He, H.Y. Kong

Ji-Huan He

The oscillatory diameter of the charged jet during the bubble electrospinning results in beads on the obtained nanofibers. We demonstrate that the applied voltage and the initial flow rate of the jet are the crucial parameters that are necessary to control morphology of the nanofibers. We also find that there is a criterion for production of smooth nanofibers without beads. The theory developed in this paper can be extended to the classical electrospinning and the blown bubble-spinning.

Fractal Harmonic Law And Waterproof/Dustproof, Hai-Yan Kong, Rou-Xi Chen, Ji-Huan He

Ji-Huan He

The fractal harmonic law admits that the friction between the pure water and the moving surface is the minimum when fractal dimensions of water in Angstrom scale are equal to fractal dimensions of the moving surface in micro scale. In the paper, the fractal harmonic law is applied to demonstrate the mechanism of waterproof/ dustproof. The waterproof phenomenon of goose feathers and lotus leaves is illustrated to verify our results and experimental results agree well with our theoretical analysis.

Connecting Research On Social Issues In Nanotechnology: The Center For Nanotechnology In Society At Arizona State University, Jan Youtie, Philip Shapira

Philip Shapira

Central to the emergence of new research topics is the creation of a research network. This paper looks at the creation of a network of researchers of social issues in nanotechnology and the role of the Center for Nanotechnology in Society at Arizona State University (CNS-ASU) in the creation of this network. While there has been US investment in societal research on nanotechnology, a debate exists about the extent to which a research community has been created through these investments. This paper uses three approaches to examine the extent to which CNS-ASU is associated with the development of a research …

A Study Of Titania Nanotube Synthesis In Chloride-Ion-Containing Media, E. Panaitescu, C. Richter, L. Menon

Eugen Panaitescu

We have completed a detailed experimental investigation into the recently discovered synthesis of titania nanotubes in chloride-ion-containing media. We show that the role of the chloride ions is catalytic and it has a strong effect in increasing the reactivity of the solution, while the nature of cations has no visible role. We have identified the critical parameters for optimal growth and fast production of nanotubes, and a basic growth mechanism for the tubes is proposed. This opens routes for significant improvements of the method toward uniformity and/or better overall yield, making it a viable alternative to the present established methods.

Cause And Prevention Of Moisture-Induced Degradation Of Resistance Random Access Memory Nanodevices, Albert Chen

Albert B Chen

Dielectric thin films in nanodevices may absorb moisture, leading to physical changes and property/performance degradation, such as altered data storage and readout in resistance random access memory. Here we demonstrate using a nanometallic memory that such degradation proceeds via nanoporosity, which facilitates water wetting in otherwise nonwetting dielectrics. Electric degradation only occurs when the device is in the charge-storage state, which provides a nanoscale dielectrophoretic force directing H2O to internal field centers (sites of trapped charge) to enable bond rupture and charged hydroxyl formation. While these processes are dramatically enhanced by an external DC or AC field and electron-donating electrodes, …

Functions And Future Applications Of F1 Atpase As Nanobioengine - Powering The Nanoworld!, Sandip S. Magdum

Sandip S. Magdum

Recent nanotechnological revolution mandates astonishing imagination about future nanoworld. Nature has ability to create nanobiomolecules which can function in extraordinary way which can be used to produce nano hybrid systems. The opportunity to use such nanobiomolecules in combination of nanomechanical systems for development of novel nano hybrid systems for their various applications needs to explore in further nanotechnological development. F1 ATPase is a subunit of ATP synthase, which is one of the biomolecular structure works on the plasma membrane of the living cell. The reversible function of F1 ATPase gives a counterclockwise rotation of γ shaft by hydrolyzing ATP and …

Research Inequality In Nanomedicine, Thomas Woodson

Thomas Woodson

The 10-90 gap is an idea in the healthcare literature that less than 10%of all research funding goes to solving health problems that are 90%of the global disease burden. This paper examines whether there is inequality in nanotechnology healthcare research (nanomedicine). To understand the inequality in nanomedicine, I conducted a bibliometric review of Web of Science and PubMed databases. Overall there is not large inequality in nanomedicine research. The bibliometric analysis shows that most nanomedicine research is done in high income countries, but their research portfolios extend beyond rich world diseases like Alzheimer’s disease and diabetes to include research on …

Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar

Srinivas Sridhar

Negative index metamaterials are demonstrated based on metal-dielectric nanocomposites prepared using a versatile bottom-up nanofabrication approach. The method involves the incorporation of vertically aligned metal nanowires such as Au and Ag inside dielectric aluminum oxide nanotemplates. Optical absorbance measurements show resonance peaks corresponding to the transverse and longitudinal surface plasmon modes. A quantitative model based on effective medium theory is in excellent agreement with experimental data, and points to specific composite configurations and wavelength regimes where such structures can have applications as negative refraction media for imaging.

Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar

Donald Heiman

Negative index metamaterials are demonstrated based on metal-dielectric nanocomposites prepared using a versatile bottom-up nanofabrication approach. The method involves the incorporation of vertically aligned metal nanowires such as Au and Ag inside dielectric aluminum oxide nanotemplates. Optical absorbance measurements show resonance peaks corresponding to the transverse and longitudinal surface plasmon modes. A quantitative model based on effective medium theory is in excellent agreement with experimental data, and points to specific composite configurations and wavelength regimes where such structures can have applications as negative refraction media for imaging.

Magnetic Properties Of Gamnas Nanodot Arrays Fabricated Using Porous Alumina Templates, S. Bennett, L. Menon, D. Heiman

Donald Heiman

Ordered arrays of GaMnAs magnetic semiconductor nanodots have been fabricated using anodic porous alumina templates as etch masks. The magnetic behavior is studied for prepared arrays with 40 nm dot diameter, 15 nm dot thickness, and 80 nm periodicity. The disklike nanodots exhibit an easy axis for fields applied in the radial direction and a hard axis in the smaller direction. In the radial direction superparamagnetism is observed with a blocking temperature of 30 K. The fabrication technique is convenient for preparing nanodot arrays of compound semiconductors that cannot be formed by self-assembly techniques.

Negative Index Metamaterials Based On Metal-Dielectric Nanocomposites For Imaging Applications, L. Menon, W. T. Lu, A. L. Friedman, S. P. Bennett, D. Heiman, S. Sridhar

Latika Menon

Negative index metamaterials are demonstrated based on metal-dielectric nanocomposites prepared using a versatile bottom-up nanofabrication approach. The method involves the incorporation of vertically aligned metal nanowires such as Au and Ag inside dielectric aluminum oxide nanotemplates. Optical absorbance measurements show resonance peaks corresponding to the transverse and longitudinal surface plasmon modes. A quantitative model based on effective medium theory is in excellent agreement with experimental data, and points to specific composite configurations and wavelength regimes where such structures can have applications as negative refraction media for imaging.

Magnetic Properties Of Gamnas Nanodot Arrays Fabricated Using Porous Alumina Templates, S. P. Bennett, L. Menon, D. Heiman

Latika Menon

Ordered arrays of GaMnAs magnetic semiconductor nanodots have been fabricated using anodic porous alumina templates as etch masks. The magnetic behavior is studied for prepared arrays with 40 nm dot diameter, 15 nm dot thickness, and 80 nm periodicity. The disklike nanodots exhibit an easy axis for fields applied in the radial direction and a hard axis in the smaller direction. In the radial direction superparamagnetism is observed with a blocking temperature of 30 K. The fabrication technique is convenient for preparing nanodot arrays of compound semiconductors that cannot be formed by self-assembly techniques.

A Study Of Titania Nanotube Synthesis In Chloride-Ion-Containing Media, E. Panaitescu, C. Richter, L. Menon

Latika Menon

We have completed a detailed experimental investigation into the recently discovered synthesis of titania nanotubes in chloride-ion-containing media. We show that the role of the chloride ions is catalytic and it has a strong effect in increasing the reactivity of the solution, while the nature of cations has no visible role. We have identified the critical parameters for optimal growth and fast production of nanotubes, and a basic growth mechanism for the tubes is proposed. This opens routes for significant improvements of the method toward uniformity and/or better overall yield, making it a viable alternative to the present established methods.

High-Throughput Assembly Of Nanoelements In Nanoporous Alumina Templates, Evin Gultepe, Dattatri K. Nagesha, Latika Menon, Ahmed A. Busnaina, Srinivas Sridhar

Srinivas Sridhar

The authors demonstrate a nanofabrication method utilizing nanoporous alumina templates which involves directed three dimensional assembly of nanoparticles inside the pores by means of an electrophoretic technique. In their demonstration, they have assembled polystyrene nanobeads with diameter of 50 nm inside nanopore arrays of height of 250 nm and diameter of 80 nm. Such a technique is particularly useful for large-scale, rapid assembly of nanoelements for potential device applications.

Directed Assembly Of Gold Nanoparticle Nanowires And Networks For Nanodevices, Xugang Xiong, Ahmed A. Busnaina, Selvapraba Selvarasah, Sivasubramanian Somu, Ming Wei, Joey Mead, Chia-Ling Chen, Juan Aceros, Prashanth Makaram, Mehmet R. Dokmeci

Sivasubramanian Somu

Alternating electric field is used to assemble gold nanoparticle nanowires from liquid suspensions. The effects of electrode geometry and the dielectrophoresis force on the chaining and branching of nanowire formation are investigated. The nanowire assembly processes are modeled using finite element calculations, and the particle trajectories under the combined influence of dielectrophoresis force and viscous drag are simulated. Nanoparticle nanowires with 10 nm resolution are fabricated. The wires can be further oriented along an externally introduced flow. This work provides an approach towards rapid assembly and organization of ultrasmall nanoparticle networks.

Scalable Nanotemplate Assisted Directed Assembly Of Single Walled Carbon Nanotubes For Nanoscale Devices, Prashanth Makaram, Sivasubramanian Somu, Xugang Xiong, Ahmed A. Busnaina, Yung-Joon Jung, Nicol E. Mcgruer

Sivasubramanian Somu

The authors demonstrate precise alignment and controlled assembly of single wall nanotube (SWNT) bundles at a fast rate over large areas by combining electrophoresis and dip coating processes. SWNTs in solution are assembled on prepatterned features that are 80 nm wide and separated by 200 nm. The results show that the direction of substrate withdrawal significantly affects the orientation and alignment of the assembled SWNT bundles. I-V characterization is carried out to demonstrate electrical continuity of these assembled SWNT bundles.

Effect Of Temperature On Surface Tension Of A Bubble And Hierarchical Ruptured Bubbles For Nanofiber Fabrication, Ji-Huan He

Ji-Huan He

Polymer bubbles can be used to fabrication of nanofibers using the bubble electrospinning. Temperature is one of the most effective parameters to control the spinning process. Suitable choice of inner and outer temperatures results in a minimal surface tension. A bubble under electronic field will be broken to form daughter bubble cascades, which can be used for nanofiber fabrication.

Review On Fiber Morphology Obtained By Bubble Electrospinning And Blown Bubble Spinning, Ji-Huan He, Hai-Yan Kong, Rui-Rui Yang, Hao Dou, Naeem Faraz, Liang Wang, Chao Feng

Ji-Huan He

Here we show an intriguing phenomenon in the bubble electrospinning process that the ruptured film might be stripped upwards by an electronic force to form a very thin and long plate-like strip, which might been received in the metal receiver as discontinuous backbone-like wrinkled materials, rather than smooth nanofibers or microspheres. The processes are called the bubble electrospinning. The electronic force can be replaced by a blowing air, and the process is called as the blown bubble spinning. We demonstrate that the size and thickness of the ruptured film are the crucial parameters that are necessary to understand the various …

Low-Voltage And Short-Channel Pentacene Field-Effect Transistors With Top-Contact Geometry Using Parylene-C Shadow Masks, Yoonyoung Chung, Boris Murmann, Selvapraba Selvarasah, Mehmet Dokmeci, Zhenan Bao

Mehmet R. Dokmeci

We have fabricated high-performance top-contact pentacene field-effect transistors using a nanometer-scale gate dielectric and parylene-C shadow masks. The high-capacitance gate dielectric, deposited by atomic layer deposition of aluminum oxide, resulted in a low operating voltage of 2.5 V. The flexible and conformal parylene-C shadow masks allowed fabrication of transistors with channel lengths of L = 5, 10, and 20 μm. The field-effect mobility of the transistors was μ = 1.14 (±0.08) cm²/V s on average, and the IMAX/IMIN ratio was greater than 10⁶.