Drawing Power From the Martian Breeze

Inspired by aspen leaves, researchers at the University of Warwick believe they can increase the life expectancy of robots exploring Mars—or any other slightly windy planet. Even though the Mars Opportunity rover had an impressive run—15 years—it depended for energy on its solar panels, and when a planet-wide dust storm blocked sunlight, the rover’s fate was sealed.

The Warwick scientists have devised an energy-harvesting mechanism that could be used as an emergency generator. Using mathematical modeling to better understand the physical properties that make the aspen leaf tremble in the slightest breeze—notably, the flat shape of its stem—they designed a mechanical equivalent. The resulting device uses a cantilever beam to mimic the stem and a curved blade tip with a circular arc cross section acting like the main leaf. Low-speed wind tunnel tests found it more responsive than the blunter bodies typically envisioned for energy harvesters—making it ideal for the anemic atmosphere and thin winds on Mars.