According to them, there is a large amount of electromagnetic energy all around us which has not been explored sufficiently. Therefore, they has been using inkjet printers to print the energy antennas on a variety of paper and plastic using an ink emulsion of silver nanoparticles active as printed radio-frequency sensors and circuits.
These antenna can tap into electromagnetic currents of FM radio, television station, radar… with a wide spectrum of frequencies from 100 MHz to 15 GHz or higher. Then, it enables wireless sensors to tap into electromagnetic currents in the air around them and converts it to a direct current or stores the captured microwave energy in capacitors or batteries.
With the electronic current up to 50 MW, this type of antenna can power for wireless sensors and small microprocessor.
Source: “Hoat dong khoa hoc” magazine