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Full-Text Articles in Mechanical Engineering
Advanced Techniques For Carbon Nanotube Templated Microfabrication, Jason Matthew Lund
Advanced Techniques For Carbon Nanotube Templated Microfabrication, Jason Matthew Lund
Theses and Dissertations
Carbon nanotube templated microfabrication (CNT-M) is a term describing a grouping of processes where carbon nanotubes (CNTs) serve a structural role in the fabrication of a material or device. In its basic form, CNT-M is comprised of two steps: produce a template made from carbon nanotubes and infiltrate the porous template with an additional material. Vertically aligned carbon nanotube (VACNT) templates can be grown to heights ranging from microns to millimeters and lithographically patterned to a desired form. Deposition of an existing thin film material onto a CNT template will coat all template surfaces and can produce a near solid …
Electrostatically Actuated Double Wall Carbon Nanotubes To Include Intertube Van Der Waals Forces, Ezequiel Juarez Ocanas
Electrostatically Actuated Double Wall Carbon Nanotubes To Include Intertube Van Der Waals Forces, Ezequiel Juarez Ocanas
Theses and Dissertations
This work deals with the amplitude-frequency and amplitude-voltage responses of parametric and primary resonances of electrostatically actuated double-walled carbon nanotubes (DWCNTs). Nonlinear forces acting on the DWCNT are intertube van der Waals and electrostatic forces. Soft AC excitation and small viscous damping are assumed. In coaxial vibration, the outer and inner carbon nanotubes move together (in-phase), maintaining their geometric concentricity; while in noncoaxial vibration, the CNTs move in opposite direction (out-of-phase). Modal coordinate transformation is formulated. The Harmonic Balance Method (HBM) is used to find the free response solutions of the DWCNT. The Reduced Order Model (ROM) method is also …
Functional Porous Polydimethlysiloxane As Piezoresistive And Piezoelectric Materials, Taissa Rose Michel
Functional Porous Polydimethlysiloxane As Piezoresistive And Piezoelectric Materials, Taissa Rose Michel
Theses and Dissertations
In this paper, polydimethylsiloxane (PDMS), carbon nanotubes (CNTs), and zinc oxide (ZnO) were combined to create functionalized piezoresistive and piezoelectric sensors for pressure sensing and energy harvesting. Samples were foamed to show that the increased deformability of the foam sensors makes them suitable for a range of applications including dexterous robotics, tactile sensing, energy harvesting, and biosensing. Uniform dispersion of CNTs was achieved with chloroform as the solvent. Samples were foamed using chemical blowing and scaffolding but granulated sugar at 70% porosity resulted in foamed samples with the most consistent mechanical properties. Samples underwent tensile and compressive testing for their …
Nonlinear Dynamics Of Electrostatically Actuated Nanotweezers, Bin Liu
Nonlinear Dynamics Of Electrostatically Actuated Nanotweezers, Bin Liu
Theses and Dissertations
Bin Liu, Nonlinear Dynamics of Electrostatically Actuated Nanotweezers. Master of Science (MS), May 2016, 77 pp, 6 tables, 59 figures, references, 25 titles. The amplitude-frequency response of electrostatic nanotube nanotweezer device system is investigated; soft alter current was setting at near half natural frequency impulse on nanotubes which are referred to as two arms, parametric and primary resonances will be shown in the results, respectively. Firstly we are using the Method of Multiple Scales (MMS) analytical model; results will be compared with Reduced Order Model (ROM). By variation and comparison of multiple parameters including van der wall molecular forces, electrostatic …
Design Exploration And Analysis Of Carbon-Infiltrated Carbon Nanotube Vascular Stents, Darrell John Skousen
Design Exploration And Analysis Of Carbon-Infiltrated Carbon Nanotube Vascular Stents, Darrell John Skousen
Theses and Dissertations
The purpose of this research was to design, develop, and test coronary stent designs composed of carbon-infiltrated carbon nanotubes (CI-CNTs). Coronary stents currently have two major complications: restenosis and thrombosis. CI-CNT stents have potential to address both of these issues, and therefore may provide improved clinical outcomes. CI-CNT stent geometry is patterned using high-resolution photolithography that provide advantages in design possibilities.To develop a coronary stent, a standard design process was followed including: background, design specifications, concept generation, development, analysis, and testing. Background research was first completed and general design specifications for coronary stent performance were compiled. Multiple design concepts were …
An Exploration Of Carbon-Filled Carbon Nanotubes As A Potential Material In Coronary Stents, Kristopher Neil Jones
An Exploration Of Carbon-Filled Carbon Nanotubes As A Potential Material In Coronary Stents, Kristopher Neil Jones
Theses and Dissertations
The purpose of this research is to explore the potential of using carbon-infiltrated carbon nanotubes (CI-CNT) as a material for coronary artery stents. Stents are commonly fabricated from metal, which may not perform as well as many polymers and ceramics in biomedical applications. Pyrolytic carbon, a ceramic, is currently used in medical implant devices due to its preferrable biocompatibility properties. Micro-patterned pyrolytic carbon devices can be created by growing carbon nanotubes, and then filling the space between with amorphous carbon via chemical vapor deposition. We prepared multiple samples of two different planar stent-like flexible geometries and smaller cubic structures out …
Mathematical Model And Experimental Exploration Of The Nanoinjector Lance Array, Nathan C. Toone
Mathematical Model And Experimental Exploration Of The Nanoinjector Lance Array, Nathan C. Toone
Theses and Dissertations
The Nanoinjector Lance Array has been developed to inject foreign material into thousands of cells at once using electrophoresis to attract and repel particles to and from the electrically-charged lances. A mathematical computer model simulating the motion of attracted or repelled proteins informs the design of the nanoinjection lance array system. The model is validated by accurately predicting protein velocity in electrophoresis experiments. A complete analysis of parameters is conducted via simulations and specific research questions regarding the counter electrode of the nanoinjector lance array system are explored using the model. A novel technique for fabricating lance arrays from collapsed …
Mechanical Properties And Mems Applications Of Carbon-Infiltrated Carbon Nanotube Forests, Walter C. Fazio
Mechanical Properties And Mems Applications Of Carbon-Infiltrated Carbon Nanotube Forests, Walter C. Fazio
Theses and Dissertations
This work explores the use of carbon-infiltrated carbon nanotube (CI-CNT) forests as a material for fabricating compliant MEMS devices. The impacts of iron catalyst layer thickness and carbon infiltration time are examined. An iron layer of 7nm or 10nm with an infiltration time of 30 minutes produces CI-CNT best suited for compliant applications. Average maximum strains of 2% and 2.48% were observed for these parameters. The corresponding elastic moduli were 5.4 GPa and 4.1 GPa, respectively. A direct comparison of similar geometry suggested CI-CNT is 80% more flexible than single-crystal silicon. A torsional testing procedure provided an initial shear modulus …
Straightness Of Growth For Carbon Nanotube Microelectromechanical Systems, Kellen S. Moulton
Straightness Of Growth For Carbon Nanotube Microelectromechanical Systems, Kellen S. Moulton
Theses and Dissertations
The purpose of this research is to examine the effect of iron catalyst thickness on the straightness of growth of carbon nanotube microelectromechanical systems (CNT-MEMS). One of the key benefits of CNT-MEMS is that they can potentially have very high aspect ratios. One of the challenges in attaining these high aspect ratios is maintaining device straightness; as these devices get taller, the edges tend to curve rather than grow straight vertically. Scanning electron mi- croscope images of samples grown using various iron catalyst thicknesses show that both straight growth and relatively good edge definition can be achieved using iron thicknesses …