Filtering by
- All Subjects: nanotechnology
- All Subjects: Radiation
- Creators: Kozicki, Michael
The tool, referred to as Deppy, deposits material via hypersonic impaction, a two chamber process that takes advantage of compressible fluids operating in the choked flow regime to accelerate particles to up several thousand meters per second before they impact and stick to the substrate. This allows for the energetic separation of the synthesis and deposition processes while still behaving as a continuous flow reactor giving Deppy the unique ability to independently control the particle properties and the deposited film properties. While the ultimate goal is to design a tool capable of producing a broad range of nanomaterial films, this work will showcase Deppy's ability to produce silicon nano-particle films as a proof of concept.
By adjusting parameters in the upstream chamber the particle composition was varied from completely amorphous to highly crystalline as confirmed by Raman spectroscopy. By adjusting parameters in the downstream chamber significant variation of the film's density was achieved. Further it was shown that the system is capable of making these adjustments in each chamber without affecting the operation of the other.
Computational Fluid Dynamics (CFD) software, ANSYS Fluent, is utilized to simulate two-phase flows consisting of a carrier gas (Helium) and silicon nanoparticles. The Cunningham Correction Factor is used to account for non-continuous effects at the relatively low pressures utilized in AD.
The nozzle, referred to herein as a boundary layer compensation (BLC) nozzle, comprises an area-ratio which is larger than traditionally designed nozzles to compensate for the thick boundary layer which forms within the viscosity-affected carrier gas flow. As a result, nanoparticles impact the substrate at velocities up to 300 times faster than the baseline nozzle.
So far only microscale radial structures and electrodeposits have been fabricated which limits their use to labeling only high value items due to high cost associated with their fabrication and analysis. Therefore, there is a need for a simple recipe for fabrication of macroscale structure that does not need sophisticated lithography tools and cleanroom environment. Moreover, the growth kinetics and material characteristics of such macroscale electrodeposits need to be investigated. In this thesis, a recipe for fabrication of centimeter scale radial structure for growing Ag electrodeposits using simple fabrication techniques was proposed. Fractal analysis of an electrodeposit suggested information capacity of 1.27 x 1019. The kinetics of growth were investigated by electrical characterization of the full cell and only solid electrolyte at different temperatures. It was found that mass transport of ions is the rate limiting process in the growth. Materials and optical characterization techniques revealed that the subtle relief like structure and consequently distinct optical response of the electrodeposit provides an added layer of security. Thus, the enormous information capacity, ease of fabrication and simplicity of analysis make macroscale fractal electrodeposits grown in radial programmable metallization cells excellent candidates for application as physical unclonable functions.
This is a test plan document for Team Aegis' capstone project that has the goal of mitigating single event upsets in NAND flash memory caused by space radiation.
In collaboration with Moog Broad Reach and Arizona State University, a<br/>team of five undergraduate students designed a hardware design solution for<br/>protecting flash memory data in a spaced-based radioactive environment. Team<br/>Aegis have been working on the research, design, and implementation of a<br/>Verilog- and Python-based error correction code using a Reed-Solomon method<br/>to identify bit changes of error code. For an additional senior design project, a<br/>Python code was implemented that runs statistical analysis to identify whether<br/>the error correction code is more effective than a triple-redundancy check as well<br/>as determining if the presence of errors can be modeled by a regression model.