Leaking microwave ovens can power kitchen gadgets

New Scientist : Despite safeguards, some microwaves leak out of microwave ovens. Health and safety regulations in the US mandate that at a distance of 5 cm from the oven, the radiative power should not exceed 5 milliwatts/cm ². Most ovens typically radiate just 0.5 mW/cm ². Even though the level is low, Yoshihiro Kawahara of the University of Tokyo and his collaborators at Georgia Tech have demonstrated that leaking microwaves could power electronic egg-timers, meat thermometers, and other low-power kitchen gadgets. Their prototype energy harvester combines a 1-cm-long antenna with circuitry for generating electricity. Tests suggest that equipping a low-power gadget with the harvester and keeping it close to the microwave oven would obviate the need to use mains or battery power to keep it going.