Adam Konneker and Dr. David Allred, Department of Physics and Astronomy
Over the course of the past year, I have had the invaluable opportunity to pursue a research project under the guidance of Dr. David Allred. I am still working on completing the project, but I have made significant progress and gained experience in designing microscale devices. The original goal of my research project was to design and build a microscale acceleration sensor, or accelerometer, capable of operating in extreme environments, which is to say in high temperatures and corrosive atmospheres. This project is one piece of a larger goal, which is to make wireless sensors for extreme environments. Thus far, I have been able to complete the design of several comb capacitor structures, which are essentially fixed accelerometers. In principle, adding a simple spring structure is all that is required to make them functioning accelerometers.
As I worked on the initial design for the accelerometer, it was decided that the most prudent course of action would be to work on an antenna structure simultaneously and perform a series of feasibility tests with simplified devices. These simplified devices consist of static combcapacitors attached to antennas, which were designed by another student. The purpose of these structures is to serve as a passive radar targets. The sensors can be interrogated with a radar signal composed of a somewhat broad spread of frequencies, and the structure will reflect back a much smaller band centered around its resonance frequency. By changing the value of the capacitor, the resonant frequency of the structure can be modified, and in this way the magnitude of the acceleration can be deduced. The simplified structures will be used in tests to determine the usable range of the devices and the robustness of the experimental carbon nanotube-metal composite with which the devices will be constructed.
During the course of the year I experienced several significant technical difficulties which prevented me from completing the fabrication of any test structures. The first challenge was with the photolithography process, which is the first step in creating the devices. I had experience using photolithography from previous research projects, but I encountered a problem which I had never seen before. In the end, I determined that much of the problem was due to a malfunctioning ultraviolet lamp in a machine used to complete the process. A broken valve in another piece of equipment halted my progress for several more weeks, as well. Despite these setbacks, however, I believe that I have had a reasonably successful year, and now that the equipment problems have been sorted out I will be able to move forward again. I expect to have completed sensors to test in the next two months, and then I will be able to perform a variety of tests to measure range, frequency response, and mechanical robustness of the structures. I will also perform tests to determine the sensors ability to withstand and operate in high temperatures. After an initial battery of tests are performed, I will make refinements to the fabrication process and design structures with fully functioning accelerometers.
