China Focus: New self-powered sensing system sheds light on environmental monitoring

LANZHOU -- A type of self-powered and self-calibrated sensing system has been newly developed by Chinese researchers, casting light on real-time environmental monitoring in diverse environments, according to Lanzhou University in Northwest China's Gansu province.

This system advances practical applications of self-powered sensing technology, and provides new solutions for the efficient utilization of energy in a wide range of environments, the university said.

Driven by the mechanical energy of irregular raindrops -- this system can accurately monitor environmental temperature and humidity in real time.

The study, conducted by researchers from the School of Materials and Energy at Lanzhou University, has been published in the journal Science Advances.

"We proposed a new practical strategy to tackle difficulties in the real-time environmental monitoring sector by calibrating the power generation of irregular energy in real time, thereby ensuring that the powered sensors can accurately measure the sensing signals," said Liu Shuhai, a professor at the school.

Liu explained that there is a large amount of irregular environmental energy that is hard to use directly for real-time environmental monitoring, such as the mechanical energy of raindrops or falling leaves, as well as wind energy and solar energy.

Current environmental monitoring systems mostly rely on batteries, while it is difficult and troublesome to replace these batteries. Besides, nanogenerators are difficult to use directly for real-time monitoring due to their low energy density and the high irregularity of their output current, according to Liu.

The research team proposed this new type of self-powered and self-calibrated environmental monitoring system composed of a tribo-electric nanogenerator, a calibration resistor and a sensor network in parallel, for real-time temperature and humidity monitoring.

The calibration resistor can monitor in real time the irregular output of a tribo-electric nanogenerator produced by the irregularity of rainfall.

This system uses the calibrating signal to calibrate the sensing signal in real time, achieving accurate sensing with an error margin of less than 5 percent. It is suitable for scenarios where sensors are widely distributed but not able to be powered by batteries or where it is difficult to replace batteries.

It can be deployed in complex environments, such as remote areas and forests, to assist with ecological protection, disaster early warning, meteorological monitoring and more.

"This new strategy provides broader prospects for the efficient utilization of environmental energy with features of low energy density and extreme irregularity. Looking ahead, it can be integrated with multiple clean energy options, such as solar and wind energy, to further expand application scenarios," said Liu.