Pohang University of Science and University (POSTECH, Chancellor Kim Do-yeon) developed high-efficient piezoelectric device that is harmless to human body and does not cause any adverse reaction even when it is attached inside of a body by using onion peel that is composed of cellulose fibers.
POSTECH announced on the 15th that Professor Kim Ji-gon of Chemical Engineering Department’s Block Copolymer Self-Assembly Research Group and a research team led by Ph.D. Sandip Maiti co-developed piezoelectric device that creates high power efficiency through onion peel that does not require any chemical processes with a research team led by Professor Khatua of Indian Institute of Technology Kharagpur.
Piezoelectric nano-generator is a device that changes pressure into electricity when force or stimulation is applied. Usually when force is applied, electric charges are divided into positive and negative electric charges and cause piezoelectric effects that have electricity flowing as density of electric charges on a surface is changed.

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<Concept diagram of Professor Kim Ji-gon’s research team’s high-efficient piezoelectric device composed of onion peel’s cellulose component>

Piezoelectric device can be attached to a human body or a device and it can change various energies such as one’s movement, wind, or vibration into electric energy.
However it was difficult to make previous piezoelectric devices that had used harmful substances biodegradable, suitable for human bodies, and compose matters and they are very expensive.
Research team hypothesized that crystallinity from arrangement of cellulose fibers can produce piezoelectric effect and confirmed that energy can be obtained from onion peel through tests. Based on this test, it was able to develop high-efficient device that has high durability and is very sensitive as it can produce electricity just from simple movement of a leaf.
“It was meaningful to develop a generator that can produce power from natural raw material that does not pollute environment.” said Professor Kim Ji-gon. “This device will become a basis for developing energy source for next-generation devices such as wearable devices.”
Staff Reporter Jung, Jaehoon | jhoon@etnews.com