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Mechanical Engineering. 2006;128(04):26-30. doi:10.1115/1.2006-APR-1.
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This paper elaborates increasing use of microelectromechanical systems (MEMS) in aerospace industry. MEMS are chip-size devices usually carved from semiconductor wafers. Jet engines running lean fuel mixtures are prone to instability. High-temperature MEMS sensors could improve performance and fuel mileage while reducing emissions. The paper also discusses different MEMS structures, as MEMS structures vary greatly. The oscillating proofmass structures sense angular rotation around an axis in the gyro on the right. The industry has also begun to build a more innovation-ready infrastructure. The MEMS and Nanotechnology Exchange provides another way to ease the tortuous path to commercialization. It promises more prototypes, and more technologies will flow from MEMS inventors in the future. However, experts believe that the real problem is that until more MEMS companies begin making money in aerospace, venture capitalists hesitate to fund their companies.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2006;128(04):31-33. doi:10.1115/1.2006-APR-2.
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The atomic force microscope (AFM) is enabling engineers to understand mechanical systems at the most basic level. The heart of the AFM is a probe comprising a microfabricated cantilever with an extraordinarily sharp tip. The AFM tip can be thought of as a nanometer-scale finger that we have at our disposal to interface with matter on the scale of individual molecules, and even atoms. The paper highlights that it is the only instrument that allows us to ‘touch’ the surface of a sample with nanometer-scale resolution and atomic-level force sensitivity. Researchers using AFM have now established that after relatively weak bonds break, untying segments of a relatively large structural molecule, the energy needed to stretch the untied segment can be orders of magnitude larger than the broken bond's energy. The AFM has evolved into a highly modular instrument. Advanced AFMs such as the BioScope II from Veeco Instruments operate in liquid to image and probe biologically important matter, both organic and synthetic. Also, there are AFMs for operating in vacuum, useful in investigating properties of matter without a water layer adsorbed on it, or for probing tip-sample interactions with highly sensitive probes in long range or in contact.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2006;128(04):36-38. doi:10.1115/1.2006-APR-3.
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This paper analyzes research work on developing techniques to study complex fluids. Although several computational fluid dynamics (CFD) vendors now sell desktop software that mechanical engineers can buy to model complex flows, many problems are still simply too hard for those applications. According to engineers, CFD programs for these complex problems can take years to write, even with the supercomputer's aid. Moreover, some flows may never be modeled: they are just too complex for even the most advanced software. Behr and a colleague, Matteo Pasquali, an Associate Professor in the Department of Chemical and Biomolecular Engineering at Rice University, are now at work writing a CFD application that will help a heart-pump manufacturer analyze how blood would move through different configurations of the pump. Pasquali and Behr spent two years trying to turn the pump geometry and performance data Baylor provided into usable data. They converted the pump's computer-aided design information and input it into their homegrown CFD program, then came up with software tools to rotate one part of the computationally meshed pump element with respect to another.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2006;128(04):40-42. doi:10.1115/1.2006-APR-4.
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This paper discusses engineering design ideas employed by P. Wirzius Heavy Assembly GmbH of Hinden, Germany, to transport heavy loads across states. In order to find a safe way to cross its bridges, Wirzius enlisted a specialist in getting heavy objects safely to their destinations, Greiner Vehicle Technology, an engineering company based in Neuenstein, Germany. Greiner says it designs systems for transporting large machinery by road or rail. Working with Wirzius, the Greiner company devised a plan to transfer some of the extraordinary vehicle weight to a temporary track system that would channel that part of the load directly to the bridge piers. Engineers working in 3D simulated the system in motion and avoided problems, like collisions, that would otherwise have needed correction later. Crews from Greiner and Wirzius tested the system at the former Butzweilerhof Airport in Ossendorf. A transport vehicle had to transport 295 tons of ballast across a 14S-meter track. The next day, they repeated the test as a demonstration for French motorway authorities.

Commentary by Dr. Valentin Fuster

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