September 27, 2012 – A device that measures very thin quantities of liquid, such as the synovial fluid in knee joints, and a device that measures change in mass when a microdevice adsorbs small amounts of material earned top honors in Sandia National Labs’ annual student design contest for microelectromechanical system (MEMS) devices.

Texas Tech took top "novel design" honors with a micro-rheometer device that can measure the behavior of very thin quantities of liquid, such as the synovial fluid in knee joints. The method requires much smaller samples compared to macro-scale rheometers. "It is much easier, and usually less painful, to obtain small quantities of bodily fluids from patients," according to the students’ submission.

Texas Tech proposes to create a micro-rheometer to measure very thin quantities
of liquid, like that found in knee joints. (Image courtesy of Texas Tech U.)

Carnegie Mellon students won in the education category, for a device that measures the (relatively large) change in mass with a microdevice material adsorbtion, which alters the vibrational frequencies of the system. This could identify surface changes in the structure — e.g., water vapor on MEMS devices may reduce the fatigue strength of polysilicon MEMS, while hydrocarbons adsorb onto microrelay contacts and increase their electrical resistance.

Both schools were repeat winners from Sandia’s 2011 MEMS competition. Last year Texas Tech showed off an ingenious, dust-sized dragonfly with surveillance possibilities, while Carnegie Mellon won acclaim for an ultrasensitive microvalve to control very small fluid flows.

Carnegie Mellon students made use of the relatively large change in mass that occurs when a microdevice adsorbs even a small amount of material. (Image courtesy of Carnegie Mellon U.)

The nine-month-long University Alliance Design Competition is a program geared around MEMS design, fabrication and test, with one category emphasizing novel design concepts, and another category emphasizing unique structure design and its use as an educational tool for MEMS or science education. Students developed ideas for a device, created and analyzed a design model, and submitted the design to be judged by Sandia’s MEMS experts and university professors. The designs were fabbed at Sandia’s Microsystems and Engineering Sciences Applications (MESA) facility using its "Summit V" (Ultra-planar, Multi-level MEMS Technology 5) — a five-layer polycrystalline silicon surface micromachining process (one ground plane/electrical interconnect layer and four mechanical layers). Designs were then shipped back to the university students to test whether the final product matches the purpose of the original computer simulation.

This year’s event attracted nine universities, up from five in 2011, partly due to added participation from Mexican universities: the Air Force Institute of Technology, Arizona State U., Central New Mexico Community College, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional of Mexico City, Carnegie Mellon U., Southwestern Indian Polytechnic Institute, Texas Tech U., Universidad de Autonoma de Ciudad Juarez, Universidad de Guadalajara, Universidad de Guanajuato, U. of Oklahoma, U. of Utah, and Universidad Veracruzana. (The two winners, plus Arizona, Oklahoma, and the AFIT, were the 2011 participants.)

For more information regarding the University Alliance and the design competition, contact Stephanie Johnson at [email protected].

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