Manos Tentzeris displays an inkjet-printed rectifying antenna used to convert microwave energy to DC power. This grid is printed on flexible Kapton material and is expected to operate with frequencies as high as 10 gigahertz when complete. (Credit: Gary Meek)
GEORIGIA TECH (US) — A new way to capture and harness energy from the air could lead to paper-based wireless sensors that are self-powered, low-cost, and able to function independently almost anywhere.
“There is a large amount of electromagnetic energy all around us, but nobody has been able to tap into it,” says Manos Tentzeris, professor of electrical and computer engineering at Georgia Institute of Technology (Georgia Tech).
“We are using an ultra-wideband antenna that lets us exploit a variety of signals in different frequency ranges, giving us greatly increased power-gathering capability.”
Inkjet printers are used to combine sensors, antennas, and energy-grabbing capabilities on paper or flexible polymers. The resulting self-powered wireless sensors may be used for chemical, biological, heat, and stress sensing for defense and industry; radio-frequency identification (RFID) tagging for manufacturing and shipping, and monitoring tasks in a variety of fields including communications and power usage.
Communications devices transmit energy in many different frequency ranges, or bands. The team’s scavenging devices are able to capture the energy, convert it from AC to DC, and then store it in capacitors and batteries. The scavenging technology can presently take advantage of frequencies from FM radio to radar, a range spanning 100 megahertz (MHz) to 15 gigahertz (GHz) or higher.
Experiments utilizing TV bands have already yielded power amounting to hundreds of microwatts. Multi-band systems are expected to generate one milliwatt or more—enough power to operate many small electronic devices, including a variety of sensors and microprocessors.