TREE

Researchers at MIT have designed a novel device the size of a U.S. quarter that harvests energy from low-frequency vibrations, such as those that might be felt along a pipeline or bridge. The tiny energy harvester — known technically as a microelectromechanical system, or MEMS — picks up a wider range of vibrations than current designs, and is able to generate 100 times the power of devices of similar size. To harvest electricity from environmental vibrations, researchers have typically looked to piezoelectric materials, or PZT, such as quartz and other crystals. Various designs are based on a small microchip with layers of PZT glued to the top of a tiny cantilever beam. As the chip is exposed to vibrations, the beam moves up and down like a wobbly diving board, bending and stressing the PZT layers. The stressed material builds up an electric charge, which can be picked up by arrays of tiny electrodes. However, the beam itself has a resonant frequency and outside of this frequency, the...

Technology is advancing at an alarming pace. Many of us in the market for auto sound systems have been more than surprised at many of the choices on the market today. Sound systems have gone far beyond the simple tuners of days past and are incorporating other features into the sound system as well. Today you can find all kinds of bells and whistles with price tags to match. It would be very easy to spend two or three thousand dollars in the purchase and installation of a very nice auto sound system in your car, truck, or SUV. Most of us, however, would do just as well with a simple three hundred dollar sound system and would be unlikely to use many of the features that the higher price sound systems offer. That being said, if you plan to be in the market for an auto sound system, a DVD players/entertainment system, an MP3 player, a CD player, and/or a navigation system for your vehicle, then you might want to select one of the more feature rich auto systems that are available on the m...