Wireless sensor networks are hot, hot hot. Even though great strides have been made to get the nodes as frugal with energy as possible, we still need better batteries and power sources for them.
Another Bit Closer to Death
Right now, wireless nodes are limited by their battery life so it's very heartening to see a real push towards exploring energy harvesting, hybrid power sources, and better batteries.
Our first example comes from a story in The Maui News. A Hawaiian company, Ambient Micro LLC, has developed a device that collects stray electromagnetic waves or photons. Sounds pretty promising, right? Especially when you consider how much stray EM radiation is wafting around in our first world environments. Well, the U.S. Air Force apparently agrees, because it gave the company a contract to develop a tiny power supply for sensors on small unmanned aerial vehicles.
A recent press release from the Hanover Trade Fair discusses the fact that the Fraunhofer Institute, a German R&D powerhouse, is working on a combination of approaches to address the proliferation of mobile and power-hungry devices in our lives. Researchers displayed a flat micro fuel cell capable of providing (when several are connected in series) 1.5 V; they've also created other micro fuel cell systems with power ratings anywhere from a couple of milliwatts up to several hundred watts. In addition to working on energy harvesting ideas, they, too, are trying to create smaller, denser energy sources.
Finally, closer to home, DARPA is looking for research proposals for "micro-meter scale energy storage," citing the need for smaller, more power-dense power sources to feed unmanned reconnaissance vehicles and remote sensors.
Mutterings about new batteries, fuel cells, and energy harvesting aren't new. What is new, at least to me, is that there are finally some working prototypes and products out there.