John Harb

• Brigham Young University

Microelectrode arrays of carbon nanotube (CNT)/carbon composite posts with high aspect ratio and millimeter-length were fabricated using carbon-nanotube-templated microfabrication with a sacrificial "hedge". The high aspect ratio, mechanical robustness, and electrical conductivity of these electrodes make them a potential candidate for next-generat...

Over the last decade, DNA origami has matured into one of the most powerful bottom-up nanofabrication techniques. It enables both the fabrication of nanoparticles of arbitrary two-dimensional or three-dimensional shapes, and the spatial organization of any DNA-linked nanomaterial, such as carbon nanotubes, quantum dots, or proteins at ∼5-nm resolut...

This work examines anisotropic electroless plating of DNA-functionalized gold nanorods attached to a DNA origami template to fabricate continuous metal structures of rectangle, square and T shapes. DNA origami, a versatile method for assembling a variety of 2- and 3-D nanostructures, is utilized to construct the DNA breadboard template used for thi...

A nanoporous carbon monolith structure has been developed for use as a scaffold for silicon anodes for lithium batteries. This scaffold was fabricated by coating vertically aligned carbon nanotubes in a highly conformal coating of nanocrystalline carbon, applied via atmospheric pressure chemical vapor deposition. The coating increases the mechanica...

In this study, silicon-coated vertically aligned carbon nanotube (Si-VACNT) electrodes were used to examine the impact of encapsulation, which effectively reduced the surface area exposed to the electrolyte. This system is ideal for examining the influence of an electrolyte-blocking layer due to its well-defined geometry and high aspect ratio. The...

An improved method for the metallization of DNA origami is examined in this work. DNA origami, a simple and robust method for creating a wide variety of nanostructured shapes and patterns, provides an enabling template for bottom-up fabrication of next-generation nanodevices. Selective metallization of these DNA templates is needed to make nanoelec...

In this study, the impact of galvanic coupling of magnesium to steel on the corrosion rate, surface morphology, and surface film formation was investigated. In particular, experiments were performed to examine and quantify the role of self-corrosion (also called negative difference effect (NDE) or anodic hydrogen) during the corrosion of galvanical...

In this study, the impact of galvanic coupling of magnesium to steel on the corrosion rate, surface morphology, and surface film formation was investigated. In particular, experiments were performed to examine and quantify the role of self-corrosion (also called negative difference effect (NDE) or anodic hydrogen) during the corrosion of galvanical...

In battery-aware design, knowledge of the interaction between the duty cycle and battery performance isused to provide improvements in battery life beyond those achievable through low-power design alone. To that end, this study examined experimentally the influence of wireless sensing duty cycles on battery performance and capacity for small autono...

Over 2 million miles of pipeline in the United States alone are used to transport a variety of products that include natural gas, crude oil, and petrochemicals [1]. Pipelines are also essential for water distribution. A breech in pipe integrity due to corrosion leads to a disruption of service and, in the worst case, a catastrophic accident or envi...

This work examines the selective deposition of two different metals on a single DNA origami template that was designed and assembled to direct the deposition. As a result, we were able to direct copper and gold to pre-designated locations on the template, as verified by both compositional and morphological data, to form a heterogeneous Cu-Au juncti...

DNA origami is a valuable technique in arranging nanoparticles into various geometries with a 100 nm footprint, high resolution, and experimental simplicity. Aligned nanoparticles, in addition to being used for photonics, can also be utilized to create thin metal wires with intricate and asymmetric junctions. Many factors affect the yield and densi...

This paper demonstrates the use of galvanic displacement to form continuous tellurium-based nanowires on DNA templates, enabling the conversion of metals, which can be deposited site-specifically, into other materials needed for device fabrication. Specifically, galvanic displacement reaction of copper and nickel nanowires is used to fabricate tell...

An understanding of the pulse discharge behavior of commercial lithium coin cells in wireless sensing systems (WSs) is critical to prolonging the operating life and/or reducing the size of such systems. This paper is part of an effort to examine, model and optimize battery performance for sensor duty cycles consisting of multiple pulse discharges....

This work demonstrates the use of a circuit-like DNA origami structure as a template to fabricate conductive gold and copper nanostructures on Si surfaces. We improved over previous results by using multiple Pd seeding steps to increase seed uniformity and density. Our process has also been characterized through atomic force microscopy, particle si...

We show controllable patterning of palladium nanoparticles in both one and two dimensions using electron beam lithography and reactive ion etching of a thin film of polyacrylic acid (PAA). After initial patterning of the PAA, a monolayer of polystyrene-b-poly-2-vinylpyridine micelles is spun cast onto the surface. A short reactive ion etch is then...

Nanostructured materials are increasingly important for the construction of electrochemical energy storage devices that will meet the needs of portable nanodevices. Here we describe the development of a nanoenergy storage system based on inorganic mineral phases contained in ferritin proteins. The electrochemical cell consists of an anode containin...

DNA origami is a promising tool for use as a template in the design and fabrication of nanoscale structures. The ability to engineer selected staple strands on a DNA origami structure provides a high density of addressable locations across the structure. Here we report a method using site-specific attachment of gold nanoparticles to modified staple...

This paper examines the use of amine-functionalized templates to create nanopatterned metal features. A key aspect of the work is the use of an additive to increase the plating density and enable continuous metallization of nanoscale features. Specifically, MPS (3-mercapto-1-propane sulfonate) was found to increase the plating density of copper on...

The goal of this work is to deposit nanoscale metal features on a nonconductive substrate in a specific and controlled manner in order to make nanoscale devices. To this end we studied the effects of several plating additives on electroless plating of nanoscale-thin layers in a model system, namely palladium metal on plain and chemically modified s...

Dielectrophoresis has been used as a technique for the parallel localization and alignment of both semiconducting and metallic carbon nanotubes (CNTs) at junctions between electrodes. A variation of this technique known as floating potential dielectrophoresis (FPD) allows for a self-limiting number of CNTs to be localized at each junction, on a mas...

Self-assembly of organic thiols is the most common way to introduce functional groups onto gold surfaces. Although the gold–sulfur (Au–S) bond is moderately strong (45 kcal/mol), it is also prone to oxidation, which substantially weakens the Au–S interaction. In this work, we describe the creation of more robust molecular assemblies on gold. As a f...

This work focuses on metallization of lambda DNA and DNA origami on surfaces, as a step toward application in nanocircuit fabrication. We have succeeded in forming continuous Pd and Aunanowires using lambda DNA, and branched Aunanostructures using DNA origami. The approach we describe here is simple and efficient compared with prior work, enabling...

We have used block copolymer patterned arrays of 5 nm gold nanoparticles (AuNPs) for chemically aligned surface attachment of DNA origami. Addition of single-stranded DNA-thiol to AuNPs allowed a base paired attachment of sticky end modified DNA origami. Results indicate a stable, selective attachment between the DNA origami and ssDNA modified AuNP...

This work examines the metallization of folded DNA, known as DNA origami, as an enabling step toward the use of such DNA as templates for nanoelectronic circuits. DNA origami, a simple and robust method for creating a wide variety of shapes and patterns, makes possible the increased complexity and flexibility needed for both the design and assembly...

This work encompasses modeling and experimental work to improve understanding of transport and other resistances for LiFePO4 composite cathodes used in Li-ion batteries. Modeling LiFePO4 active material requires consideration of the carbon coating around the particle, phase-change behavior, and diffusion in only one of the lattice dimensions of the...

An accurate assessment of liquid-phase mass transport resistances is necessary for understanding and optimizing battery performance using mathematical models. This work combines modeling and experiments to quantify tortuosity in electrolyte-filled porous battery structures (separator and active-material film). Tortuosities of separators were measur...

Dielectrophoresis has been used to place nanotubes, nanorods, nanowires, and other nanostructures between surface patterned metal electrodes. This technique can deposit a varying number of structures between each set of electrodes. We have developed a method to control the number of deposited singled-walled carbon nanotubes by tuning the impedance...

In superconformal filling of copper-chip interconnects, organic additives are used to fill high-aspect-ratio trenches or vias from the bottom up. In this study we report on the development of intermolecular potentials and use molecular dynamics simulations to provide insight into the molecular function of an organic additive (3-mercaptopropanesulfo...

This poster briefly describes efforts to combine the complementary advantages of bottom-up self-assembly with top-down patterning, with the goal of providing a process for fabrication of nanoelectronic circuits. Efforts are focused on the development and refinement of four key technologies: (1) solution-phase assembly of structures and templates, (...

In this work, we present a mathematical model and associated experiments for describing the performance of porous electrodes under high rates of charge and discharge. By increasing the physical accuracy of porous battery modeling, we hope to enable improved design of cells for high-power applications, such as hybrid and plug-in-hybrid electric vehi...

We report the first, successful, partial nanoshaving of octadecyl- and octyl- dimethylmonochlorosilane monolayers on silicon dioxide, as well as nanografting of perfluorinated- and amino- silanes on these substrates, using an atomic force microscopy (AFM) tip. Even partial nanografting of aminosilane patterns can be used for DNA localization or for...

Miniaturized devices for electric field gradient focusing (EFGF) were developed that consist of a cylindrical separation channel surrounded by an acrylic-based polymer hydrogel. The ionic transport properties of the hydrogel enable the manipulation of the electric field inside the separation channel. A changing cross-section design was used in whic...

We describe the preparation of homogeneous olefin-terminated monolayers on scribed silicon made from 1,9-decadiene, and mixed monolayers with varying degrees of olefin termination prepared from 1,9-decadiene and 1-decene or 1-octene, and their subsequent reactions with bromine, osmium tetroxide, dicholorocarbene, and Grubbs' catalyst. Each of these...

This paper documents an experimental study to compare the behavior of bis-(3-sodiumsulfopropyl) disulfide (SPS)-Cl polyethylene glycol (PEG) and 3-mercaptopropanesulfonic acid sodium salt (MPSA)-Cl-PEG additive systems during copper electrodeposition. These systems are analogous to those used industrially to plate copper lines onto integrated circu...

The TIM (Thermomechanical In-plane Microactuator) is a thermal actuator that offers a high output force at a low input voltage, in a design that can be easily modified to match force and displacement requirements of various applications. The purpose of this paper is to examine factors that affect the steady-state power requirements of a TIM. Reduci...

The electrochemical analysis was carried out by the electrochemical reduction of horse spleen ferritin (HoSF) using oxidized methyl viologen. The reduction and oxidation peaks of the methyl viologen and released Fe appeared on the cyclic voltammogram. The Fe was released on reduction of the HoSF by the methyl viologen. The effect of oxidized methyl...

This paper describes the fabrication and testing of LiFePO4 cathodes for hybrid vehicle applications. The cathodes contained combinations of three different carbon conductivity additives: vapor-grown carbon fibers (CF), carbon black (CB) and graphite (GR). Cells of different carbon composition and active-material loading were tested with 10 s charg...

In this Proceedings we show surface passivation for chemically templated growth on patterned surfaces. Our ultimate goal is to chemically pattern insulating substrates at nanometer dimensions and to grow metal lines by electroless deposition in the patterned regions. We investigate a series of monofunctional silanes of the general formula ClSi(CH3)...

Azotobacter vinelandii bacterioferritin (AvBF) containing 800-1500 Co or Mn atoms as Co(III) and Mn(III) oxyhydroxide cores (Co-AvBF, Mn-AvBF) was synthesized by the same procedure used previously for horse spleen ferritin (HoSF). The kinetics of reduction of Co-AvBF and Mn-AvBF by ascorbic acid are first-order in each reactant. The rate constant f...

Horse spleen ferritin (HoSF) containing 800-1500 cobalt or 250-1200 manganese atoms as Co(O)OH and Mn(O)OH mineral cores within the HoSF interior (Co-HoSF and Mn-HoSF) was synthesized, and the chemical reactivity, kinetics of reduction, and the reduction potentials were measured. Microcoulometric and chemical reduction of HoSF containing the M(O)OH...

Electrical conductivity measurements were performed on single apoferritin and holoferritin molecules by conductive atomic force microscopy. Conductivity of self-assembled monolayer films of ferritin molecules on gold surfaces was also measured. Holoferritin was 5-15 times more conductive than apoferritin, indicating that for holoferritin most elect...

Three-branched DNA molecules have been designed and assembled from oligonucleotide components. These nucleic acid constructs contain double- and single-stranded regions that control the hybridization behavior of the assembly. Specific localization of a single streptavidin molecule at the center of the DNA complex has been investigated as a model sy...

We present a simple classical method for treating charge mobility in metals adjacent to liquid solutions. The method, known as electrode charge dynamics, effectively bridges the computational gap between ab initio calculations on small metal clusters and large-scale simulations of metal surfaces with arbitrary geometry. We have obtained model param...

Currently available power storage systems, such as those used to supply power to microelectronic devices, typically consist of a single centralized canister and a series of wires to supply electrical power to where it is needed in a circuit. As the size of electrical circuits and components become smaller, there exists a need for a distributed powe...

The concept of a bio-nanobattery is based on ferritin, an iron storage protein that naturally exists in most biological systems. Biomineralization allows ferritins to reconstitute iron core with various metallic cores. When the ferritin half cells are integrated into a complete battery system, the fabrication of well-organized ferritin arrays is ne...

The present study examines the electrochemical behavior of cobalt, iron, and manganese mineral cores in horse spleen ferritin (HoSF). Ferritins are spherical proteins 12 nm in diameter composed of 24 subunits arranged to enclose a central hollow cavity ~8 nm in diameter. Up to 4000 iron atoms can be sequestered inside the cavity as a ferrihydrite (...

This paper presents a simple low-power control circuit intended to manage the power within a remote autonomous microsystem hybrid power supply. A hybrid power supply has only recently been discussed in the literature as a microsystem power source solution. The power management circuitry, which is a key component within a hybrid power supply, has no...

This paper describes the development of a thick-film microcathode for use in Li-ion microbatteries in order to provide increased power and energy per area. These cathodes take advantage of a composite porous electrode structure, utilizing carbon nanotubes (CNT) as the conductive filler. The use of carbon nanotubes was found to significantly reduce...

We will present electrical measurement on the conductivity of ferritin molecules by conductive AFM. The high stability of ferritin relative to other proteins makes them attractive for nanotechnology applications such as nanoscale batteries. Ferritins are very stable, biological molecules found widely distributed in nature that are responsible for m...

Nickel-zinc microbatteries have been constructed for use in wireless microsensors and similar microsystems. A high power density is required for the batteries to meet the size and power requirements of these systems. A mathematical model of the side-by-side nickel-zinc cell was developed and used to increase the power density cell geometry by optim...

Horse spleen ferritin with iron core (Fe-ferritin) and the ferritin reconstituted with cobalt (Co-ferritin) are considered for the concept of a bio-nanobattery that will be a key element to a distributed energy storage system. The Co-ferritin has a good stability and was successfully synthesized and tested for reducing capability. The redox potenti...

Molecular dynamics simulations have been carried out for aqueous electrolyte solutions between model electrode surfaces. The effect of solvent model flexibility on bulk and double layer properties was observed for electrode surface charge densities of 0, ±0.1, and ±0.2 C/m 2 and ion concentrations of 0, 0.5, and 1 M. Two flexible models were used t...

This paper documents an experimental investigation of additive behavior in acidic copper plating solutions containing chloride ions, polyethylene glycol (PEG), and bis-(3-sodiumsulfopropyl disulfide) (SPS). These solutions represent a simplified model of solutions used industrially for electroplating copper interconnects. Experiments were conducted...

We are investigating the possibility of using ferritin protein molecules as the basis of a nanoscale battery. Ferritin molecules will self assembly on gold surfaces to form a single monolayer electrode. AFM was used to study this assembly on atomically flat gold surfaces. The electron transfer rate through the ferritin protein shell is a potential...

Thermomechanical microactuators possess a number of desirable attributes including ease of fabrication and large force and displacement capabilities relative to other types of microactuators. These advantages provide motivation for improving thermomechanical microactuator designs that are more energy efficient and thus better suited for low-power a...

This paper describes the characteristics of microbatteries suitable for use in a hybrid micropower supply for powering autonomous MEMS and other microsystems. The hybrid power supply includes an energy conversion device, microscopic batteries for energy storage, and control/interface circuitry. Comparison of the hybrid approach with single power so...

A deposit sintering model has been developed and integrated into the comprehensive combustion code PCGC-3. Comparisons of model predictions with experimental data from a pilot-scale facility indicate that the model adequately represents key physical processes. The model should therefore be useful for predicting the ash deposition behavior of a vari...

Our experience with the development of an outcomes-based educational plan to satisfy ABET EC 2000 is documented. Critical aspects of our plan include: the method used to define student outcomes; definition of mastery levels that reflect the relative importance of individual outcomes; definition of a core set of outcomes targeted for mastery by all...

Microscopic nickel-zinc batteries have been built using microfabrication procedures similar to those used in the microelectronics industry. These batteries were designed for use with autonomous microsystems and are of particular interest for applications that involve remote sensing. It is envisioned that the batteries would be part of a hybrid micr...

This paper describes the design of a hybrid power system for use with autonomous MEMS and other microdevices. This hybrid power system includes energy conversion and storage along with an electronic system for managing the collection and distribution of power. It offers flexibility and longevity in a compact package. The hybrid power system couples...

Lacking from much of MEMS technology is a viable strategy for supplying power. In particular, MEMS intended to be autonomous require microscopic energy storage. The purpose of this paper is to discuss the design of microscopic batteries to fill this need. Energy storage strategies for MEMS, and design considerations for batteries, are reviewed. The...

This paper describes electrochemical behavior of microscopic batteries based on both the lithium/ion and Ni/Zn couples. These batteries are being developed for use in MEMS devices and other microelectronics, especially remote, autonomous sensors. Many of these applications require a combination of long cycle life, moderate energy storage capability...

A concept is presented for remote, autonomous sensors, which includes an on-board power supply, signal transmission, a sensing element, and a controller. Sensors can be deployed without direct connection for either signal transmission or energy supply. The power supply can be used to power many types of remote sensors, and includes microscopic batt...

Detailed analyses of coal ash deposits were performed with the use of SEM, X-ray, and image analysis in order to characterize local deposit properties as a function of position. Such analyses are important for understanding and predicting the thermal and physical properties of ash deposits. The present study used measurements of deposit composition...

A mathematical model has been developed in order to simulate the three‐dimensional, transient behavior during discharge of a spirally wound lead‐acid battery cell designed for use in hybrid‐electric vehicles. Several aspects of battery behavior are predicted, including potential and current distributions, heat generation rates, concentration change...

The purpose of the present study was to combine a detailed fundamental model of a lead-acid battery with the ADVISOR vehicle simulation package developed by the U.S. Department of Energy's National Renewable Energy Laboratory (NREL). Use of fundamentally based models has the potential to significantly increase the predictive capability, flexibility...

This paper documents our experience with the development of an educational plan designed to satisfy the requirements of ABET 2000. The paper first presents the overall structure of the plan which includes both a process loop and a product loop, with assessment and feedback at multiple levels. Our progress on the initial pass through the process loo...

Discusses the needs of freshmen chemical engineering students in terms of courses related to the field. Describes the nature and content of a course designed to involve freshmen in a chemical engineering curriculum. (DDR)

First-year students interested in studying an engineering discipline need an introduction to that discipline that is both broad and meaningful. Most do not have sufficient information about the discipline to finalize their choice of major. Also, those who remain in the major lack an overall view of the discipline and fail to recognize connections b...

Traditional approaches to the prediction of the deposition behavior of a coal usually involve the use of empirical indices and ASTM ash fusion temperatures. These approaches, however, can give misleading results and are often unreliable. In recent years, considerable effort has been made in the development of models which overcome some of the defic...

This article combines Writing Across the Curriculum (WAC) assignments and the learning styles theory of David Kolb to enhance learning through writing in engineering education. Writing assignments are categorized by their appeal to each of four types of learners: divergers (Type 1), assimilators (Type 2), convergers (Type 3), and assimilators (Type...

Examines issues related to incorporating an equation-solving software package into the undergraduate curriculum in chemical engineering. Observations and conclusions apply to equation-solving packages other than Mathcad. (DDR)

Data from computer controlled scanning electron microscopy (CCSEM) are typically interpreted by grouping particles into bins based on their elemental compositions. Some of the bins correspond to well-defined mineralogical species or phases with known properties. Other bins are defined for convenience so that similar particles can be grouped togethe...

The purpose of this work was to characterize a set of deposit samples with respect to their compositions, phases present, and morphology. An understanding of how these properties change as a deposit grows is essential to developing a physical picture of deposit behavior, especially transitions in behavior from heterogeneous agglomerations of partic...

The ash transformation and deposition behavior of pyrite and illite, which are commonly identified with slagging, are influenced by the manner in which the minerals occur in the fuel. An enhanced computer controlled scanning electron microscopy technique was used to analyze the mineral content of individual coal particles in samples of two pulveriz...

The character of fireside ash deposits depend on the processes by which deposits are formed and subsequent reactions within the deposit and with furnace gases. The properties influencing furnace heat transfer, absorptivity for radiative transfer and thermal conductivity for conductive transfer are shown from many measurements to depend on this char...

Prediction of ash behavior in boilers has, for many years, been based on relatively simple relationships involving the composition of inorganic material in fuels. In recent years, advanced analyses for both fuels and deposits have seen increasing use in the solid fuel combustion community. The combination of the standard and advanced analyses, toge...

Two subbituminous coals from the Powder River Basin were fired in a pilot-scale combustor to study ash deposit formation under low-temperature fouling conditions. The two coals were chosen as they are similar in composition, but behaved differently when fired in a utility boiler. This study focuses on the mechanisms governing the formation of the i...

Emission Fourier transform, infrare (FTIR) spectroscopy data provide in situ, time-resolved, spectralemissivity measurements for ash deposits generated from two U.S. Powder River Basin coals. The first 3h of deposit growth on a tube in cross flow in a pilot-scale furnace detail the development of surface emissivity with time. Measured emissivities...

The character of fireside ash deposites depend on the propocesses by which deposits are formed and subsequent reactions within the deposit and with furnancegases. The properties influencing furnance heat transfer. absorptivity for radiative transfer and thermal conductivity for conductive transfer are shown from many measurements to dependent on th...

This workshop introduces a method for the enhancement of engineering education based on learning style theory. The material is presented in three parts. The first part describes four learning styles or preferences which are derived from the manner in which individuals perceive and process information. Part two of the presentation is designed to fac...

Thrust Area 2, Fuel Minerals, Fouling, and Slagging, is focused on obtaining a clear understanding of the role of fuel inorganic components in combustion processes. During the combustion process, the inorganic components are transformed to ash. The principal problems associated with ash are deposition on heat-transfer surfaces, erosion, corrosion,...

In situ Fourier transform infrared (FTIR) emission spectroscopy is used to identify the presence of silica, sulfates, and silicates as a function of time in coal ash deposits generated in Sandia's multifuel combustor, a pilot-scale reactor. Ash deposits are formed on a cylindrical tube in cross flow under experimental conditions which correspond to...