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Full-Text Articles in Mechanical Engineering

Polyimide/Silicon Dioxide Nanocomposites As Dielectrics For Helium-Cooled High-Temperature Superconducting Cables, Harrison Michael Hones Jun 2020

Polyimide/Silicon Dioxide Nanocomposites As Dielectrics For Helium-Cooled High-Temperature Superconducting Cables, Harrison Michael Hones

Theses and Dissertations

In this thesis, polyimide (PI) and silicon dioxide (SiO2) were combined in the form of a nanocomposite for use as a dielectric on helium-cooled high-temperature superconducting (HTS) cables. Further, a cryogenic chamber was designed with the intent of cooling samples to 40 K for dielectric and thermal contraction testing. Composites were created through an in situ process which resulted in nanoparticle formation within the host matrix. Samples were tested for dielectric strength at room temperature (300 K) as well as cryogenic temperature (92 K) using liquid nitrogen as the coolant. Composite samples tested at 300 K averaged a dielectric strength …


Characterization Of Reactive Ion Etch Chemistries Using Direct Write Lithography, Dylan T. Martin-Abood Mar 2020

Characterization Of Reactive Ion Etch Chemistries Using Direct Write Lithography, Dylan T. Martin-Abood

Theses and Dissertations

The DoD requires a variety of COTS and number of custom microelectronics to provide important functionality to critical military systems. Photolithography and DRIE are two techniques commonly used in the development of deep anisotropic features for the fabrication and modification of microelectronics and MEMS. However, standard photolithography techniques are ineffective for unique substrate geometries and DRIE processes require a chemical passivation step only applicable to Si substrates. This work confirmed the capability of RIE using DWL to perform deep, highly selective, anisotropic etching on elevated, non-circular substrates.