Ambient electromagnetic energy exists all around us, emitted from sources such as television transmitters, mobile phone networks and satellite communication systems. A team of researchers at Georgia Tech School of Electrical and Computer Engineering are developing a multitude of devices for harnessing this ambient electromagnetic energy. The research team are creating an energy scavenging functionality by using inkjet technology to combine sensors and antenna, all printed on paper or flexible polymer. While paper based sensors tend to function at frequencies of around 100-200 megahertz, polymer based sensors tend can function at up to around 15-60 gigahertz. The production process involves inkjet-dispensing an emulsion of silver nanoparticles to create self powering wireless sensors. These devices capture ambient energy transmitted from communications devices, convert it from AC to DC and then store it in batteries or capacitors. The frequencies which can be scavenged by these devices range from around 100 megahertz to 15 gigahertz.
While this technology is still in development, the team have set their expectations for their devices to be able to generate over a milliwatt of scavenged energy (enough to operate many small electronic devices). With the integration of super capacitors it is possible that these scavenging devices could power electronic devices requiring over 50 milliwatts of energy (for shorter periods). This technology could also be used as a form of back-up for energy systems when they fail. Scavenged energy could be used to power the wireless communications required to alert remote personnel of the system’s energy failures while also keeping critical functionalities online. The team at Georgia Tech believe that in the future, paper based energy scavenging devices will be widely available at low cost and will bring massive benefit to fields such as: airport security, home energy savings, food quality maintenance and bio-monitoring devices.
Tim Phillips, Catenary Solutions