During the Fall 2015 semester, the Fraunhofer Center for Coatings and Diamond Technologies (Fraunhofer CCD) elected to sponsor a team of four MSU Electrical and Computer Engineering students in their semester-long senior design project: Monitoring of a Diamond Polishing System. CCD project engineer Aaron Hardy familiarized the design team with the polishing equipment and facilitated visits for data collection and in-situ testing throughout the semester. The team, consisting of Paul Dionese, Alex Kohler, Rohan Panda, and Anthony Garvert, developed a microphone-based system to monitor the polishing acoustically.
Mechanical polishing of single and polycrystalline diamond are routine tasks at Fraunhofer CCD. Whether the polished sample is needed for optical analysis, as a substrate for additional diamond growth, or as an electrode where contacts will be annealed, polishing is a critical step. The smoothness of the polished surface can determine the success or failure of all subsequent steps; therefore, a system for monitoring the progress of diamond polishing would be immensely useful for process development toward smoother and more consistent polished diamond surfaces.
Equipped with a microphone and an accelerometer, the design team created a device that would send frequency data through an Arduino UNO board to a digital display, and optionally, to a computer connected via USB. The accelerometer attaches to the polishing arm and serves as an alarm system, triggering a horn if the output exceeds a certain threshold. The power supply and microphone amplifier were designed in EAGLE and made into a PCB.
MSU College of Engineering’s Design Day is a valuable opportunity for students to apply the skills they have gained in the classroom to real-world, sponsored projects. Fraunhofer CCD is grateful for the opportunity to sponsor such a team and looks forward to more collaboration in the future.