Engineers in some circles have questioned the life expectancy of shape memory alloys (SMAs), which undergo a solid-state phase change when cooled and return to their original shape when heated. The flap over it may be unjustified. After seeing an article on SMAs in the 04.21.03 issue of Design News, astute reader Victor Rossi brought to our attention a demonstration that's been operating in the lobby of Dynalloy, a manufacturer of Flexinol® SMAs, since 1985. The butterfly, an early prototype of ones sold in stores, has been flapping its SMA-powered wings 6 million times a year for 18 years. Dynalloy President and Founder Wayne Brown says that the company is so confident of Flexinol's performance that it offers a one-year warranty on the butterfly, no questions asked. Of the 50,000 butterflies purchased each year, customers return only about 1%. "We perform a kind of equivalent of an Alien Autopsy to determine what went wrong, and even send the owner an official autopsy report," he says. "The SMA is never the culprit. It's almost always a circuit failure, or the dog ate it."
What makes this movie stand out from the typical high school sports story is that the teenagers are undocumented immigrants, and the big game is a NASA-sponsored marine robotics competition. Like many other Hollywood movies, however, Spare Parts only tells part of the story. What the film shows -- and doesn’t show -- raises important issues affecting STEM education in the US.
Instead of sifting through huge amounts of technical data looking for answers to assembly problems, engineers can now benefit from 3M's new initiative -- 3M Assembly Solutions. The company has organized its wealth of adhesive and tape solutions into six typical application areas, making it easier to find the best products to solve their real-world assembly and bonding problems.
Load dump occurs when a discharged battery is disconnected while the alternator is generating current and other loads remain on the alternator circuit. If left alone, the electrical spikes and transients will be transmitted along the power line, leading to malfunctions in individual electronics/sensors or permanent damage to the vehicle’s electronic system. Bottom line: An uncontrolled load dump threatens the overall safety and reliability of the vehicle.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.