ISR News Story
Hanrahan, Waits, Ghodssi paper selected as JMM 'Highlight of 2014'
An article by alumni Brendan Hanrahan (MSE Ph.D. 2013) and Christopher Michael Waits (EE Ph.D. 2008) of the Army Research Laboratory, along with ISR Director Reza Ghodssi (ECE/ISR), has been selected as one of the Highlights of 2014 of the Journal of Micromechanics and Microengineering.
Isotropic etching technique for three-dimensional microball-bearing raceways first appeared in 2014 J. Micromech. Microeng. 24 015021. It describes a multi-step plasma etching technique to fabricate deep-grooved micro-scale ball-bearing raceways. These raceways are critical in building multiple ball-bearing supported microturbines. The deep-groove geometry employed can handle mixed axial and radial loads, allowing for stable, high-speed operation compared to previous iterations of the microball-bearing raceways.
The multi-step, inductively coupled plasma-based process is optimized to obtain <2% deviation amongst intended raceway depth, width and curvature. Etching non-uniformity is measured to be 0.15% within the raceway of a single device. The bearing dynamics with the new deep-groove geometry have been simulated. The deep-groove raceway, packed with off-the-shelf precision ball-bearings provides a stability improvement over previous demonstrations of high-performance rotary micromachines operating at high speeds.
About Highlights of 2014
About the microball-bearing work of the MEMS Sensors and Actuators Lab (MSAL)
More on Brendan Hanrahan
In addition to his engineering efforts, Hanrahan is also known for co-founding the non-profit corporation Cupid Charities, which runs the world-wide Cupid’s Undie Run event series. To date the organization has raised more than $2M for the Children’s Tumor Foundation, a not-for-profit that funds treatment and research toward neurofibromatosis, a disease can lead to painful tumors that grow on nerves and lead to blindness, disfigurement, cancer and other ailments. The event, which started in Washington, D.C. in 2010, is now held in 35 U.S. cities and in Australia. It was featured in a February 2015 Washington Post article.
February 9, 2015