I am currently researching acoustic metamaterials. Metamaterials are materials that exhibit different properties than the bulk material from which they are made. The change in material properties is caused by manipulating the structure of the materials. I am investigating how the structure of these materials affects the frequency at which they absorb sound and the amount of attenuation that can be achieved. They have great potential for advancing the possibilities of sound absorption. Furthermore, they can be used to create acoustic lenses that can be used to focus sound. Below is a picture of a preliminary design for an acoustic metamaterial sound absorber.
The four spherical structures act as Helmholtz resonators. The structure has very good sound absorption capabilities at the Helmholtz resonance frequency. The other interesting feature of these metamaterials is that they can absorb frequencies that have a wavelength which is much larger than the structure itself. Typically, low-frequency sound (long wavelength) is difficult to mitigate and can pass through structures that are much smaller than its wavelength.
Design of an Automated Turntable for Radiation Pattern Measurements
The first project that I worked on as a PhD student was the design of a turntable used to characterize the radiation pattern of speakers. For the project, I designed
the structure of the turntable, used Inventor CAD software to design a pulley and a stepper motor mount, 3D printed the parts, and programmed a RaspberryPi to control the stepper motor. I also built a VI in LabView which plays the measurement sound files through the speaker being measured, records the sound measurements from a microphone, and then sends the Raspberry Pi a signal to step one degree. Below is a link to several pictures of the project.
I am currently a graduate teaching assistant (GTA) for the Preparing the Future Professoriate course taught by the Dean of the Graduate School, Dr. Karen DePauw. During the Fall 2016 semester I was a GTA for the building vibration section of the ME 4006 lab and had a total of 80 students in my four lab sections. During the Spring of 2017 I was a GTA for the ME 4005 lab with roughly 40 students in the two lab sections. These are both upper level undergraduate labs that all mechanical engineering students at Virginia Tech are required to take. Working as a teaching assistant has been very rewarding and I have significantly improved my teaching skills and am enthusiastic to continue developing as an educator.