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Full-Text Articles in Engineering

High Speed Roll-To-Roll Printable Transistor Enabled By A Pulsed Light Curable Cnt Ink, Harish Subbaraman Jun 2019

High Speed Roll-To-Roll Printable Transistor Enabled By A Pulsed Light Curable Cnt Ink, Harish Subbaraman

Electrical and Computer Engineering Faculty Publications and Presentations

This paper reports the first high speed roll-to-roll printable transistor using a carbon nanotube (CNT) semiconducting layer. The transistor is made possible through the development of a pulsed light curable CNT ink compatible with typical drop on demand inkjet cartridges. This CNT ink uses a xylene based solvent with methanol, glycerin, and Triton X-100 modifiers to create an evaporable solution with appropriate absorption spectra for a mercury or xenon flash lamp with strong energy transmission in the UVB to mid visible light range, allowing the solution to absorb the energy from the flash lamp and evaporate. Transistor dimensions were defined …


Improving The Performance And Stability Of Flexible Pressure Sensors With An Air Gap Structure, Xiongbang Wei, Lun Xiao, Wen Huang, Jiaxuan Liao, Zhi David Chen Oct 2017

Improving The Performance And Stability Of Flexible Pressure Sensors With An Air Gap Structure, Xiongbang Wei, Lun Xiao, Wen Huang, Jiaxuan Liao, Zhi David Chen

Electrical and Computer Engineering Faculty Publications

A highly sensitive flexible resistive pressure sensor based on an air gap structure was presented. The flexible pressure sensor consists of two face to face polydimethylsiloxane (PDMS) films covered with carbon nanotubes (CNTs). The pressure sensor with a 230 μm thickness air gap has relatively high sensitivity (58.9 kPa−1 in the range of 1–5 Pa, 0.66 kPa−1 in the range of 5–100 Pa), low detectable pressure limit (1 Pa), and a short response time (less than 1 s). The test results showed that the pressure sensor with an appropriate air gap has excellent pressure sensitive performance and application …


Skin Effect Suppression In Infrared-Laser Irradiated Planar Multi-Walled Carbon Nanotube/ Cu Conductors, Kamran Keramatnejad, Yang Gao, Yunshen Zhou, Hossein Rabiee Glogir, Mengmeng Wang, Yongfeng Lu Oct 2015

Skin Effect Suppression In Infrared-Laser Irradiated Planar Multi-Walled Carbon Nanotube/ Cu Conductors, Kamran Keramatnejad, Yang Gao, Yunshen Zhou, Hossein Rabiee Glogir, Mengmeng Wang, Yongfeng Lu

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Skin effect suppression in planar multi-walled carbon nanotube (MWCNT)/Copper (Cu) conductors was realized at the 0-10 MHz frequency range through infrared laser irradiation of MWCNTs, which were coated on the surface of the Cu substrate via the electrophoretic deposition (EPD) method. The effect of laser irradiation and its power density on electrical and structural properties of the MWCNT/Cu conductors was investigated using a wavelength-tunable CO2 laser and then comparing the performance of the samples prepared at different conditions with that of pristine Cu. The irradiation at λ=9.219 μm proved to be effective in selective delivery of energy towards depths close …


Engineered Carbon-Nanotubes Based Composite Material For Rf Applications, Emmanuel Decrossas, Mahmoud El Sabbagh, Samir M. El-Ghazaly, Victor Fouad Hanna Jan 2012

Engineered Carbon-Nanotubes Based Composite Material For Rf Applications, Emmanuel Decrossas, Mahmoud El Sabbagh, Samir M. El-Ghazaly, Victor Fouad Hanna

Electrical Engineering and Computer Science - All Scholarship

Electrical properties of nano-composite materials are extracted to investigate the possibility to engineer novel material for microwave applications. A measurement setup is developed to characterize material in a powder form. The developed measurement technique is applied on nano-particles of alumina, carbon nanotubes (CNTs), and composite mixture of carbon nanotubes and alumina. The effect of packing density on dielectric constant and loss tangent is thoroughly characterized experimentally. The obtained results show that the real part of effective permittivity may be considerably enhanced by increasing the percentage of conducting nano-particles. In addition, it is possible to decrease the loss in a material …


Rigorous Characterization Of Carbon Nanotube Complex Permittivity Over A Broadband Of Rf Frequencies, Emmanuel Decrossas, Mahmoud El Sabbagh, Victor Fouad Hanna, Samir M. El-Ghazaly Jan 2012

Rigorous Characterization Of Carbon Nanotube Complex Permittivity Over A Broadband Of Rf Frequencies, Emmanuel Decrossas, Mahmoud El Sabbagh, Victor Fouad Hanna, Samir M. El-Ghazaly

Electrical Engineering and Computer Science - All Scholarship

This work presents a comprehensive characterization of the frequency dependence of the effective complex permittivity of bundled carbon nanotubes considering different densities over a broadband of frequencies from 10 MHz to 50 GHz using only one measurement setup. The extraction technique is based on rigorous modeling of coaxial and circular discontinuities using mode matching technique in conjunction with inverse optimization method to map the simulated scattering parameters to those measured by vector network analyzer. The dramatic values of complex permittivity obtained at low frequencies are physically explained by the percolation theory. The effective permittivity of a mixture of nano-particles of …


The Effect Of Contact Length On Adhesion Between Carbon Nanotubes On Silicon Dioxide, Robert C. Davis, Kaylee Mcelroy, Aaron R. Hopkins Dec 2007

The Effect Of Contact Length On Adhesion Between Carbon Nanotubes On Silicon Dioxide, Robert C. Davis, Kaylee Mcelroy, Aaron R. Hopkins

Faculty Publications

The force of adhesion was measured for single walled carbon nanotubes grown over lithographically defined silicon dioxide trenches. We varied contact lengths between the nanotubes and silicon dioxide from 230 to 850 nm. Suspended nanotubes were pushed vertically into the trenches with an atomic force microscope tip, causing them to slip along the surface. Previous work done at shorter contact lengths found that tension was constant with contact length [J. D. Whittaker et al., Nano Lett. 6, 953 (2006)]. This study finds that when the nanotube contact length approaches 1 µm, the tension at which nanotubes slip begins to increase …