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Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Brigham Young University

2020

MEMS

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Modeling And Effects Of Non-Homogeneous Infiltration On Material Properties Of Carbon-Infiltrated Carbon Nanotube Forests, Daniel Owens Snow Aug 2020

Modeling And Effects Of Non-Homogeneous Infiltration On Material Properties Of Carbon-Infiltrated Carbon Nanotube Forests, Daniel Owens Snow

Theses and Dissertations

This work investigates the material properties and production parameters of carbon infiltrated carbon nanotube structures (CI-CNT's). The impact of non homogeneous infiltration and the porosity of cross section regions, coupled with changes in designed geometry, in this case beam width, on the density and modulus of elasticity are compared. Three potential geometric models of beam cross section are proposed and evaluated. 3-point bending, SEM images, and numerical optimization are used to assess the validity of each model and the implications they have for future CI-CNT material applications. Carbon capping near exterior beam surfaces is observed and determined to be a …


Porous Silica Nanotube Thin Films As Thermally Insulating Barrier Coatings, Derric B. Syme, Jason M. Lund, Brian D. Jensen, Robert C. Davis, Richard R. Vanfleet, Brian D. Iverson Mar 2020

Porous Silica Nanotube Thin Films As Thermally Insulating Barrier Coatings, Derric B. Syme, Jason M. Lund, Brian D. Jensen, Robert C. Davis, Richard R. Vanfleet, Brian D. Iverson

Faculty Publications

The fabrication and examination of a porous silica thin film, potentially for use as an insulating thin film, were investigated. A vertically aligned carbon nanotube (CNT) forest, created by chemical vapor deposition (CVD), was used as scaffolding to construct the porous film. Silicon was deposited on the CNT forest using low-pressure CVD (LPCVD) and then oxidized to remove the CNTs and convert the silicon to silica for electrical or thermal passivation (e.g., thermal barrier). Thermal conductivity was determined using a 1D heat-transfer analysis that equated radiative heat loss in a vacuum with conduction through the substrate and thin film stack. …