Researchers develop tiny chip powered by RF with big IoT potential

Researchers at Eindhoven University of Technology (TU/e) in The Netherlands have developed a tiny 2-millimeter square chip weighing just 1.6 milligrams that could play a role in the Internet of Things (IoT).

The tiny sensor displayed on the finger of PhD-student Hao Gao. (Photo credit: Bart van Overbeeke)

The sensor does not need a battery, but its current range is only 2.5 centimeters, so researchers are working to extend that to a meter within a year and ultimately to 5 meters. The sensor has a specially developed router, with an antenna that sends radio waves to the sensors to power them, according to the university.

The sensor also is capable of operating under a layer of paint, plaster or concrete. Peter Baltus, TU/e professor of wireless technology, explains that this makes the sensor easy to incorporate in buildings, for instance by "painting" it onto the wall with the latex.

TU/e researcher Hao Gao was awarded his PhD earlier this week for his thesis in which he developed the sensor, which is based on 65-nm CMOS technology. The title of his thesis is "Fully Integrated Ultra-Low Power mm-Wave Wireless Sensor Design Methods." The integrated circuits research was done in the university's Mixed-Signal Microelectronics group and also involved the TU/e groups Electromagnetics and Signal Processing Systems, as well as the Center of Wireless Technology.

The sensor's antenna captures energy from a router, and the sensor stores that energy. Once there is enough energy, the sensor switches on, measures the temperature and sends a signal to the router. That signal has a slightly distinctive frequency, depending on the temperature measured. The router can deduce the temperature from this distinctive frequency.

The same technology enables other wireless sensors to be made, for example to measure movement, light and humidity. According to Baltus, the application areas are enormous, ranging from payment systems and wireless identification to smart buildings and industrial production systems. The university says smart buildings of the future are expected to be full of sensors that will respond to the residents' every needs, such as heating and lighting that only switches on when someone is in a room. The same technology enables other wireless sensors to be made, for example to measure movement, light and humidity.

Getting the cost of sensors low enough to be deployed on a wide scale is often a challenge. As Engadget points out, these sensors in mass production would keep the cost down to around 20 cents, making them feasible for wide deployment.

For more:
- see this release
- see this Engadget article
- see this Gizmodo article

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