Without power-consuming tuning motors and MCUs
Natural frequency can be tuned to suit the installation environment


A domestic research team has succeeded in developing an energy harvester that tunes itself and generates power by absorbing vibrational energy of various frequencies.

The research team led by Dr. Song Hyeon-cheol of the Electronic Materials Research Group at the Korea Institute of Science and Technology (KIST) announced on the 7th that they have developed an 'automatic resonance tuning energy harvester' that adjusts its natural frequency to match resonance depending on the installation environment.

Recently, energy harvesting technology, which harvests and utilizes energy that is wasted around us, such as vibration or heat, has been gaining attention. Using this, we can create devices that generate power using surrounding energy without batteries or power lines.

Energy harvesters must produce and store as much electrical energy as possible from small vibrations. To do this, they must utilize the resonance phenomenon. However, unlike energy harvesters that have a single unique frequency, the ambient vibrations we want to utilize are distributed over a wide range of frequencies.

Therefore, whenever an energy harvester is installed, its natural frequency must be tuned to the installation environment to induce resonance, which has been a major obstacle to utilizing the energy harvester.

An automatic tuning energy harvester using a motor or MCU has been developed, but there was a problem that the power generation efficiency was greatly reduced due to the considerable electric energy consumption required to drive the tuning motor and MCU.

Accordingly, the KIST research team developed an energy harvester with a structure that can self-tune to the surrounding vibration frequency without a separate electrical device. The research team attached a weight that moves autonomously inside the energy harvester.

When it senses vibrations in its surroundings, it moves to a different location on its own. An energy harvester with a changed position of the shaft has the same frequency as the external vibration and can resonate with various vibrations.

Dr. Song Hyeon-cheol, who increased the resonant frequency band by more than 1,400% compared to before, said, “The results of this research will greatly advance the time when energy harvesters can be applied to real life,” and predicted, “Self-tuning energy harvesters will play the role of autonomous independent power sources in various fields including IoT devices.”