June 21, 2011 -- A 5 x 1mm dragonfly with beating wings and an ultra-sensitive microvalve were top winners at Sandia National Lab's student design contest for micro electromechanical systesms (MEMS).
|Scanning electron microscope of Texas Tech student-designed micro-dragonfly. (Image courtesy of Texas Tech University)|
Texas Tech University designed the MEMS dragonfly, which could translate to real aerial surveillance technology. Smaller than today's state-of-the-art micro flying machines, the biologically mimetic "dragonfly" wings measure about 0.5mm long and 0.1mm wide. Small, intermittent electric currents create thermal expansion and contraction, flapping the wings. The wings' material response creates aerodynamin, efficient lift and thrust. Flapping is achieved when small intermittent electric currents cause thermal expansion and contraction in the wings. Clever engineering uses the wing material’s response to create strokes that are more aerodynamic and hence more efficient.
|Competition entry for Texas Tech's dragonfly MEMS design. (Image courtesy of Texas Tech University)|
The dragonfly's vertical flapping motion inspired the Texas Tech designers (flight is acheived via rotary and back-and-forth motion as well in nature, and via jet thrust and propellers in man-made devices). Vertical flapping maximizes wing surface area for lift, and the wings naturally cool more quickly, said Texas Tech student Sahil Oak.
The work was supervised by Tim Dallas, TTU faculty advisor.
|Carnegie Mellon student design for a MEMS-based electrostatically operated microvalve (educational category winner). (Image courtesy of Carnegie Mellon University)|
Valve motions are typically screw-based (think garden hose) or switch-based, using a ball and flapper valve (toilets).
Carnegie Mellon University's micro-switch-based valve heightens valve control when working with tiny amounts of liquid flow. The MEMS valve is modeled on electrostatically operated micro valves, said Vitali Brand, Carnegie Mellon student research lead. This valve requires only picoJoules of energy to switch its state. The test module can help determine characteristics that would create the most efficient and lowest leakage microvalves, benefitting biological research and medical analytics.
CMU professorial oversight was provided by Maarten de Boer.
Sandia will fabricate all student design submissions using its SUMMiT V advanced fabrication process in its MESA line, using five levels of polysilicon to build complex MEMS structures. Students can then test the fabricated MEMS parts in real form.
The student contest, open to institutional members of the Sandia-led MEMS University Alliance program, provides an arena for US student engineers to design and use real microdevices. Students explore ideas, create a computer model, and analyze the design prior to submission. Sandia's MEMS experts and university professors judge designs. Other institutions competing at the annual event included the universities of Oklahoma and Utah, and the Air Force Institute of Technology. SPIE provided grants to bring 26 students and 5 professors to the Sandia awards ceremony.
The MEMS University Alliance is part of Sandia's outreach to universities to improve engineering education. It is open to any US institution of higher learning, and most recently has extended an invitation to select Mexican universities to help that country develop its technological base.
The University Alliance coordinates with the Sandia-led National Institute for Nano Engineering (NINE) and the Sandia/Los Alamos Center for Integrated Nanotechnologies (CINT).
The Sandia student presentations were hosted by Tom Zipperian, group manager of MESA Microfabrication, and Keith Ortiz, manager of MEMS Technologies. For more information regarding the University Alliance and the design competition, contact Stephanie Johnson at firstname.lastname@example.org.
Images and whitepapers describing the winning designs can be found on the web at http://mems.sandia.gov/ua/contest.html.
Sandia National Laboratories is a multiprogram laboratory operated and managed by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration.