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Full-Text Articles in Physical Sciences and Mathematics
Microfabrication With Smooth, Thin Cnt/Polymer Composite Sheets, Nathan Edward Boyer
Microfabrication With Smooth, Thin Cnt/Polymer Composite Sheets, Nathan Edward Boyer
Student Works
Carbon nanotube (CNT)/polymer composite sheets can be extremely high strength and lightweight, which makes them attractive for fabrication of mechanical structures. This thesis demonstrates a method whereby smooth, thin CNT/polymer composite sheets can be fabricated and patterned on the microscale using a process of photolithography and plasma etching. CNT/polymer composites were made from CNTs grown using chemical vapor deposition using supported catalyst growth and floating catalyst growth. The composite sheets had a roughness of approximately 30nm and were about 61¼m or 261¼m depending on whether they were made from supported catalyst grown or floating catalyst grown CNTs. The composites were …
Microfabrication With Smooth, Thin Cnt/Polymer Composite Sheets, Nathan Edward Boyer
Microfabrication With Smooth, Thin Cnt/Polymer Composite Sheets, Nathan Edward Boyer
Theses and Dissertations
Carbon nanotube (CNT)/polymer composite sheets can be extremely high strength and lightweight, which makes them attractive for fabrication of mechanical structures. This thesis demonstrates a method whereby smooth, thin CNT/polymer composite sheets can be fabricated and patterned on the microscale using a process of photolithography and plasma etching. CNT/polymer composites were made from CNTs grown using chemical vapor deposition using supported catalyst growth and floating catalyst growth. The composite sheets had a roughness of approximately 30nm and were about 61¼m or 261¼m depending on whether they were made from supported catalyst grown or floating catalyst grown CNTs. The composites were …
Silicon Carbon Nanotube Lithium Ion Batteries, Lawrence Kent Barrett
Silicon Carbon Nanotube Lithium Ion Batteries, Lawrence Kent Barrett
Theses and Dissertations
Silicon has the highest theoretical capacity of any known anode material, and silicon coated carbon nanotubes (Si-CNTs) have shown promise of dramatically increasing battery capacity. However, capacity fading with cycling and low rate capability prevent widespread use. Here, three studies on differing aspects of these batteries are presented. Here, three studies on differing aspects of these batteries are presented. The first examines the rate capability of these batteries. It compares the cycling of electrodes hundreds of microns thick with and without ten micron access holes to facilitate diffusion. The holes do not improve rate capability, but thinner coatings of silicon …
Thin Films Of Carbon Nanotubes And Nanotube/Polymer Composites, Anthony D. Willey
Thin Films Of Carbon Nanotubes And Nanotube/Polymer Composites, Anthony D. Willey
Theses and Dissertations
A method is described for ultrasonically spraying thin films of carbon nanotubes that have been suspended in organic solvents. Nanotubes were sonicated in N-Methyl-2-pyrrolidone or N-Cyclohexyl-2-pyrrolidone and then sprayed onto a heated substrate using an ultrasonic spray nozzle. The solvent quickly evaporated, leaving a thin film of randomly oriented nanotubes. Film thickness was controlled by the spray time and ranged between 200-500 nm, with RMS roughness of about 40 nm. Also described is a method for creating thin (300 nm) conductive freestanding nanotube/polymer composite films by infiltrating sprayed nanotube films with polyimide.
Diode Properties Of Nanotube Networks, David D. Allred, Bryan Hicks, Stephanie Getty
Diode Properties Of Nanotube Networks, David D. Allred, Bryan Hicks, Stephanie Getty
Faculty Publications
Single-walled carbon nanotubes (SWCNT) were prepared using iron catalysts deposited by indirect evaporation on silicon substrate covered with 500 nm-thick thermal oxide. Diode SWCNT devices have been fabricated using Au and Al, as the asymmetric metal contacts, and a random network of metallic and semiconducting nanotubes as the device channel. No effort was made to align the SWCNTs or to eliminate metallic nanotubes in our devices. Asymmetric voltage-current behavior was seen. Current rectification was observed in the source-drain bias range of -3 V to +3 V. Rectification was somewhat surprising since, although metallic tubes are in the minority (~ 1/3), …
Massively Parallel Indirect Dielectrophoresis Controlled Placement Of Carbon Nanotubes, Hiram Jacob Conley
Massively Parallel Indirect Dielectrophoresis Controlled Placement Of Carbon Nanotubes, Hiram Jacob Conley
Theses and Dissertations
Placement of single walled carbon nanotubes is demonstrated through massively parallel indirect dielectrophoresis (MPID). MPID is shown to be able to control the placement of carbon tubes as well as the number of tubes placed. Lumped element analysis for AC circuits is used to model MPID. This model allows for predictions of the number of tubes that will be captured in a trap. This model has been consistent with experimental data of numbers of nanotube placed in a junction. Carbon nanotubes placed with MPID are shown to be electrically active.