Gartner published a cyclical map of emerging technologies last year showing that iot is the most expected emerging technology in 2016, and the related iot platform is also receiving strong attention and that iot technology will mature over the next 5 to 10 years. The total number of connected devices will reach even over 50 billion by 2020, and the network will include a large number of equipment in the household, ranging from smart thermostats to smart refrigerators that can wear equipment as big as smart refrigerators
Batteries, which are sometimes the cause of mobile devices and sensors, are unreliable and have to be charged or replaced on a regular basis, and may be the greatest weakness of iot. For this reason, researchers at the university of washington have come up with a good idea: to extract energy from existing radio, television, and other wireless signals, they have developed a method that allows low-energy devices such as sensors, wearable devices, and can be connected without batteries or wires。
Currently, foreign media reports that students at the school of electronic engineering of the university of washington in the united states have recently developed a new wifi technology, the greatest feature of which is that it is less than one-tenth of every ten thousand people who are currently using wifi. Most importantly, large quantities of networked equipment can also be charged through reverse wifi technology. The technology has been nominated by the mit technology review as “the 2016 10 major technological breakthroughs” and has been applied on the campus of the university of washington。
Launching radio waves, extracting power from the waves
The technique, known as passive wi-fi, is almost identical to the daily router, but more energy-efficient. For example, while the current router has a power of 100 mw, the passive wi-fi router has only a power of 10 to 50 μw, which is only one in 10,000。
The new wifi technology works in a manner similar to the rfid chip, using wi-fi backscatter communication technology. The current wifi technology provides a signal by consuming electricity; unlike this technology, it selectively reflects radio waves and “leaves” power from them。
The project's researcher, vamsitalla, stated: “the equipment using passive wi-fi technology does not in itself transmit any signals, but only produces the wifi package by way of reflection. Thus, this type of wireless launch technology is very low in energy.”
According to researchers, the work of passive wi-fi is divided into three steps: first, a simple device needs to be installed on the wall to send a simulator to the passive wi-fi sensor. Most of the electricity is spent in the process, while sensors are almost non-power-consuming。
The sensor then accepts the simulator wave, which is then digitally converted to produce the wifi data package. Finally, equipment can transmit network data to a mobile phone or router at 11 mbps per second (better than bluetooth, but slower than some household broadband)。
The low-powered wifi equipment comes from a new communications system called wi-fi backscatter, which can use radio frequencies as a source of electrical energy and will not even require batteries in the future。
Wi-fi wi-fi wireless charged direct energy from air
With the help of this technology, future devices for the networking of goods may no longer require batteries, but rather direct energy from air。
They invented this black technology, known as the wi-fi wi-fi wi-fi system, which allows us to charge equipment within a distance of 28 feet (approximately 8. 5 metres) through wi-fi signals。
The system consists of two parts: a receiver (router) and a customized sensor. “sensor's goal is to collect rf (radio frequency) power and convert it to a direct current power source”, a researcher in the project, vamsi talla, explains: “the second block, our receiver, has been tailored to a solution that uses software modifications to make routers a power source, while also acting as traditional routers.” in other words, you simply have to upgrade the traditional wi-fi router so that data and energy transmissions coexist without interference. Or, more precisely, the technology is simply the effective use of existing electricity generated by routers。
In addition to using radio frequency as a power source, engineers at the university of washington have found ways of replicating existing wi-fi signals to provide grid connectivity to batteryless equipment; this technology, known as wi-fi backscatter, is the first programme to link batteryless equipment to wi-fi infrastructure, based on earlier research that allows low power equipment such as temperature sensors to capture energy from radio, television and wireless signals。
