Artificial muscles that should give space robots animal-like flexibility and manipulation ability will get their first test on a small NASA rover destined to explore an asteroid. Under development by Dr. Yoseph Bar-Cohen of NASA's Jet Propulsion Laboratory, Pasadena, CA, two types of artificial muscles, also known electroactive polymers (EAPs), are based on a lightweight strip of highly flexible plastic that bends and functions similarly to human fingers. The first is a polymer ribbon constructed from chains of carbon, fluorine and oxygen molecules. When an electric charge flows through the ribbon, charged particles get pushed or pulled (depending on polarity) on the ribbon's two sides, causing the ribbon to bend. Using four such ribbons, Bar-Cohen has fashioned a gripper that can pick up a rock. The second consists of thin sheets wrapped into cigar-like cylinders that stretch when one side of a sheet is charged positive and the other negative. The wrapped sheet then contracts toward the center of the cylinder, forcing it to expand lengthwise. When the power is turned off, the cylinder relaxes, enabling it to manipulate loads. These strips and strings have the potential to greatly simplify robotic spacecraft tasks, lead to future development of insect-like robots that emulate biological creatures, and could also conceivably replace damaged human muscles. Circle 400.

Designers of the next generation of communication devices are looking with interest toward the work at Star*Core, a joint design center in Atlanta, GA, that combines talents from Motorola and Lucent Technologies, plus several third-party developers. Unveiled in April was their first DSP project, the SC140, which is expected to deliver 3000 MIPS or more than 1 billion multiply-accumulate (MAC) operations per second. The 16-bit core carries four MAC units to accomplish the latter. The core also offers efficient use of power, providing 0.1 mA/MIPS running at 300 MHz, with a 1.5 volt power supply. In extremely low power applications, a 120 MHz, 0.9 volt SC140 would be rated at 1200 MIPS and 480 million MAC operations per second, while dissipating only 0.066 mA/MIPS. The compiler-driven DSP architecture allows up to 90 percent of the software code required for design to be written in a high level language such as C or C++, instead of the device's native language, easing the task of migrating existing communication systems to higher performance levels. Along with the four MAC units, the SC140 is comprised of four arithmetic logic units, four bit field units, two arithmetic address units and an efficient 5-stage pipeline. Star*Core describes the SC140 as having the sheer horsepower required for demanding multichannel applications, while suiting size, power and cost needs for subscriber devices. Circle 401.