Engineering Commons^™

Capillary-Tube Package Devices For The Quantitative Performance Evaluation Of Nuclear Magnetic Resonance Spectrometers And Pulse Sequences, Lingyu Chi, Ming Huang, Annalise R. Pfaff, Jie Huang, Rex E. Gerald Ii, Klaus Woelk

Electrical and Computer Engineering Faculty Research & Creative Works

With the increased sensitivity of modern nuclear magnetic resonance (NMR) spectrometers, the minimum amount needed for chemical-shift referencing of NMR spectra has decreased to a point where a few microliters can be sufficient to observe a reference signal. The reduction in the amount of required reference material is the basis for the NMR Capillary-tube Package (CapPack) platform that utilizes capillary tubes with inner diameters smaller than 150 µm as NMR-tube inserts for external reference standards. It is shown how commercially available electrophoresis capillary tubes with outer diameters of 360 µm are filled with reference liquids or solutions and then permanently …

Simulations Of Interfacial Electrokinetics With Applications To Microfluidic Systems, Sebastian Uppapalli

UNLV Theses, Dissertations, Professional Papers, and Capstones

Electrokinetics plays an important role in facilitating fluid transport and particle manipulation in microfluidic systems. This dissertation studies the mechanics of electrokinetic phenomena for microscale particles and drops. The work aims to increase the understanding of complex electrokinetic phenomena for applications in Lab-on-Chip technology, assembly of colloidal particles and two-phase flow sensing. The standard model consisting of the Poisson-Nernst-Planck equations is used to study the electric double layer polarization of charged dielectric particles and channel wall which plays a major role in control and manipulation of colloidal particles and understanding of electrohydrodynamic flow field.

The cases of polarization of "soft" …

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.

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

Dattatri K. Nagesha

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.

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

Latika Menon

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.

Three Dimensional Controlled Assembly Of Gold Nanoparticles Using A Micromachined Platform, Nishant Khanduja, Selvapraba Selvarasah, Chia-Ling Chen, Mehmet R. Dokmeci, Xugang Xiong, Prashanth Makaram, Ahmed A. Busnaina

Ahmed A. Busnaina

By using optical lithographic procedures, the authors present a micromachined platform for large scale three dimensional (3D) assembly of gold nanoparticles with diameters of ∼ 50 nm. The gold nanoparticles are formed into 3D low resistance bridges (two terminal resistance of ∼ 40 Ω) interconnecting the two microelectrodes using ac dielectrophoresis. The thickness of the parylene interlevel dielectric can be adjusted to vary the height of the 3D platform for meeting different application requirements. This research represents a step towards realizing high density, three dimensional structures and devices for applications such as nanosensors, vertical integration of nanosystems, and characterization of …

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

Ahmed A. Busnaina

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.

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

Ahmed A. Busnaina

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.

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

Ahmed A. Busnaina

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.

Transverse Isotachophoresis Using Polyacrylamide Gel Electrodes, Mark P. Stambaugh

Master's Theses

Separation and isolation of a desired analyte from an impure sample solution containing numerous unwanted interfering agents is the first step of nearly every laboratory test performed in medicine and biology. Nucleic acids are often of particular interest to doctors and researchers, and although methods currently exist for their isolation, these procedures are costly in time, man-power, and real-estate. In addition to easing the execution of presently performed tests, mitigation or elimination of these drawbacks would make a large range of currently unperformed tests both practical and feasible.

This thesis presents a microfluidics-based approach to the isolation of nucleic acids …

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

Nicol E. McGruer

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.

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

Yung Joon Jung

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.

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

Mehmet R. Dokmeci

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.

Three Dimensional Controlled Assembly Of Gold Nanoparticles Using A Micromachined Platform, Nishant Khanduja, Selvapraba Selvarasah, Chia-Ling Chen, Mehmet R. Dokmeci, Xugang Xiong, Prashanth Makaram, Ahmed A. Busnaina

Mehmet R. Dokmeci

By using optical lithographic procedures, the authors present a micromachined platform for large scale three dimensional (3D) assembly of gold nanoparticles with diameters of ∼ 50 nm. The gold nanoparticles are formed into 3D low resistance bridges (two terminal resistance of ∼ 40 Ω) interconnecting the two microelectrodes using ac dielectrophoresis. The thickness of the parylene interlevel dielectric can be adjusted to vary the height of the 3D platform for meeting different application requirements. This research represents a step towards realizing high density, three dimensional structures and devices for applications such as nanosensors, vertical integration of nanosystems, and characterization of …

Impedance Imaging And Measurements By Micro Probes In Aqueous Environments, Tao Shang

Theses and Dissertations

The dissertation presented here describes two research projects that may, at first glance, seem unrelated. Their unifying principle is the measurement of electrical impedance for the detection and analysis of biological materials. Impedance measurements have long been employed and studied in scientific fields, and the dissertation begins with a summary of historical methodology, applications, and terminology. Utilizing impedance measurements for microscopic imaging is the driving motivation for Scanning Impedance Imaging (SII). This technique manifests the distribution of electrical impedance inside biological tissues and is described after the dissertation's introduction. SII can provide micron-scale imaging resolution by scanning a shielded microprobe …