When you turn Ojarumaru Man on, he says something (in Japanese) about the firefly on his hat and waves his tiny, 9-gram plastic arm up and down through 60 degrees of motion. Because of O-Man's peaceful, Zen-like demeanor, engineers wanted a completely silent method of actuation that would be cost-competitive with an inexpensive, single-speed motor. (In fact, the original design called for a traditional electromagnetic motor, but engineers rejected it because it was too noisy.) In this simple application, engineers mounted Oman's arm to the output shaft of a Nano-Muscle RS-70-CE actuator, which runs off of two AA batteries and uses shape memory alloys (SMAs) as the motive force. SMAs undergo a solid-state phase change when their temperature drops below a specific transition point, providing constant power output across the entire stroke length and a force-to-weight ratio on the order of 15 kgf/m2.
Nanomuscle offers a new commercial development kit for its RS-70-CE actuator for $199.95 or toy development kit for $179.95. For details, go to http://rbi.ims.ca/3849-563
This year, Design News is getting a head start on the Fourth of July celebration. In honor of our country and its legacy of engineering innovation -- in all of its forms -- we are taking you on an alphabetical tour through all 50 states to showcase interesting engineering breakthroughs and historically significant events.
Earlier this year paralyzed IndyCar drive Sam Schmidt did the seemingly impossible -- opening the qualifying rounds at Indy by driving a modified Corvette C7 Stingray around the Indianapolis Motor Speedway.
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.