Recently, a neighbor was asking about cellular technology and how it worked. After a quick, "layman's" version of electromagnetic (EM) propagation, the neighbor seemed somewhat disturbed by learning that they were being constantly bathed in these invisible radio waves. It was at that moment that the concept of "energy harvesting" made total and complete sense. After all, we are surrounded by energy of our own making, such as radio waves, as well as solar energy, all of which is available to be captured and reused.

A number of companies are making real progress toward energy-harvesting solutions, including Texas Instruments, with a solar energy harvesting kit, and AVX with high-performance capacitors to store the captured energy for reuse. This week, at Electronica 2010 in Munich, Germany, Linear Technology and Energy Micro took a further step forward with a demonstration of capturing excess wireless energy using a piezoelectric transducer and a capacitor bank for energy storage. Low-power electronic devices are well designed when they can offer extended operating lifetimes on battery power. They are truly well designed when they can operate without the battery, which is the potential offered by energy-harvesting technologies.