Wireless powered sensor deployed for asset tracking application. Credit: A*STAR IME

Energy from wireless communications signals can be captured and harvested to power low-energy electronic devices.

Wireless RADIO FREQUENCY Power Transfer Energises Asset tracking

Ever since Nikola Tesla’s first demonstration of wireless power transmission over a century ago, the technology has since come a long way. Innovations in energy harvesting mean that we can now power low-energy devices with energy harvested from various sources, such as light, heat or radio frequency (RF) signals. Of these sources, RF waves are very promising due to their easy availability.

“In our always-connected world, radio frequency waves are readily available, being generated by transmissions from wireless networks, our mobile phones and laptops. As the amount of data we transmit increases exponentially, it provides great potential for energy harvesting,” said Dr Raju Salahuddin, Scientist, Institute of Microelectronics (IME), Agency for Science, Technology and Research (A*STAR).

It means that connected devices with sensors can now derive their operating energy from RF wireless power transfer without using batteries. An example is an Internet-of-Things (IoT) deployment in a healthcare setting that tracks assets, like wheelchairs.

“Wireless-powered sensor technology will help the adoption of IoT across different sectors,” said Dr Salahuddin. “That includes machine health monitoring in heavy industries, microclimate sensing in agriculture, smart home solutions, and in manufacturing plants where limited human access is preferred due to hazardous conditions.”

Wireless powered sensor deployed for asset tracking application. Credit: A*STAR IME


When electromagnetic waves are captured and converted into usable continuous voltage (DC), it can recharge batteries, lengthen battery life, or even replace batteries—and power ultra-low consumption devices.

Currently, batteries power most IoT devices, and a battery increases the device’s cost, weight, and size. Besides, battery replacement is a costly and time-consuming process, especially when many devices are spread over wide or inaccessible areas. Hence, eliminating the need for a battery will reduce the size and cost of the device and improve its reliability, portability, ease of use, and environmental friendliness.

“Implementing this technology can help us reduce battery dependency, which will ultimately positively impact the environment,” said Dr Salahuddin. “RF energy harvesting is a ‘green’, self-sustainable operation which can potentially provide unlimited energy supply to power up low-power devices remotely.”


A*STAR’s IME has improved the system operation efficiency for RF energy harvesting capability to the sensor nodes or end terminals. The team has custom designed the antenna and energy harvesting interface to improve long-distance wireless powering sensitivity.

This technology also reduces IoT energy consumption over time. The end-to-end IoT solution tracks overall energy consumption and can allocate operations intelligently to achieve better system energy efficiency.

“RF energy harvesting can offer accurate and timely tracking of fixed and mobile assets, while improving energy efficiency. When implemented, it can help to do away with searching for critical equipment and save on down time,” said Dr Salahuddin.

Given the potential of the technology, IME plans to license it to small and medium-sized enterprises and startups. Partners will be able to utilise the RF powered or energy harvester design capabilities for asset tracking.

This can address smart nation solutions, industrial IoT, asset tracking, and environmental monitoring, which is a market that is expected to grow to US$1.09 billion by 2027, according to ResearchAndMarkets.com.

Next, the IME team has set its sights on integrating the energy harvesting technology for 5G IoTs. This will support more use cases and a larger number of nodes with lower latency, and power on even more low power wireless IoT devices.

Learn more about this exciting research here: https://www.a-star.edu.sg/ime/Research/iot-on-the-edge

A*STAR’s Institute of Microelectronics (IME)