February 20, 2009--
Pollen-Robo's luminous "eyes" cycle through five colors depending on the area's pollen count. The balloon-like robots were developed in 2006 to warn Japanese residents of impending hayfever attacks--16 percent of the nation's population suffers from pollen allergies.
Each Pollen-Robo, developed by forecaster Weathernews Inc., is 11.8 inches (30 centimeters) wide and weighs about two pounds (one kilogram).
The pollution-monitoring bots hang outside homes, absorbing the same volume of air that a person breathes. They relay pollen, temperature, air pressure, and humidity data to Weathernews for its online pollen alert map.
Like a real-life version of the title robot from the Oscar-nominated film WALL-E,
Pollen-Robos are among the droids tackling the world's environmental jobs. Such machines are reducing greenhouse gas emissions, patrolling the Amazon, and mopping up radioactive waste.
Here's a look at some of the "green" machines in development today and how they can help save the planet.
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Photograph by Yoshikazu Tsuno/AFP/Getty Images