by Stephanie Gooch

Like a hawk-eyed parent, the Hyperion rover keeps careful tabs on its Titan namesake’s child—the Sun. Using GPS receivers, odometric sensors and a clock, the solar-powered robot navigates sun-synchronously to keep itself continuously powered. Hyperion computes the relative position of the sun to the terrain and predicts where shadows will fall, planning its route accordingly. Two digital cameras map the terrain while a laser line-scanner detects immediate obstacles. A third panoramic camera records the landscape for remote observers. The four wheels are individually driven and steered by separate motors. A passive joint on the front axle allows flexible yaw and roll to eliminate energy-wasting skidding. The semi-autonomous robot can operate independently or slide in shared stages to direct teleoperation. Supported by NASA, researchers at Carnegie Mellon Robotics Institute tested their creation this summer under the midnight sun—at Haughton Crater on Devon Island. Hyperion completed 95% of its initial 6.1 km circuit autonomously while using remote supervision the remaining 5% of the journey. A second, more challenging 9.1 km experiment revealed room for software improvements. This prototype holds promise for extending the reach of remote intrastellar exploration. Circle 550-Carnegie Mellon Robotics Institute, or connect at www.RSLeads.com/110df-550

Conventional photolithography for silicon chips works on the scale of several hundred nanometers. EUV lithography uses UV wavelengths of 13 nm, promising transistor elements measuring 40 atoms in width. This scale appears to reach silicon’s limit for Moore’s law. However, one of the contenders to replace silicon is carbon, the strongest fiber in nature. In 1998 researchers at Delft University of Technology in the Netherlands succeeded in creating a transistor from a carbon nanotube (CNT), a single molecule ten atoms in width. This summer, IBM researchers have created an intramolecular logic-performing circuit, making a “NOT” gate (the O’s and 1’s of computing). A single CNT is positioned over gold electrodes to make a pair of p-type CNT field-effect transistors in series. The device is covered by a PMMA-insulated layer, and e-beam lithography opens a window to expose part of the nanotube. Potassium is evaporated through this window to convert the exposed p-type nanotube transistor into an n-type transistor (electron), while the insulated transistor remains p-type (hole). Thus ambipolar transport can be achieved. Looks like Moore’s law has an extended lease. Circle 551-IBM Research, or connect at www.RSLeads.com/110df-551