Joint Research Team of SKKU Advanced Institute of Nano Technology (SAINT) Professor Seongpil An and School of Pharmacy Professor Ki Hyun Kim

Develops High-efficiency Nano Generator Using Natural Resources

The antibacterial nano generator that can be used for electricity power source of

next-generation wearable electric devices

▲ Professor Ki Hyun Kim, SAINT Researcher Dogun Park, Professor Seongpil An

▲ School of Pharmacy Post-Doc. Researcher Joo-Hyun Hong (first co-author)

Joint research team of SAINT Professor Seongpil An and School of Pharmacy Ki Hyun Kim (first author SAINT Researcher Dogun Park, co-author School of Pharmacy Researcher Joo-Hyun Hong) announced that the team developed a high efficiency nano-generator that can use a mixture of nature-originated antibacterial materials and biocompatible polymer as electricity power source of a wearable electric device.

Recently, nano-generator, generator which can earn electricity from various kinetic energies such as vibration, impact, and bending, is gathering attention as the new next-generation renewable energy source since it can convert big/small daily-life kinetic energies to useful power. In addition, the research to apply this technology to next-generation wearable devices as its power source has been active in recent few years.

Among different types of nano-generator, the technology that harvests electric energy from friction due to contacts in between materials is called the triboelectric nanogenerator. To employ such triboelectric nanogenerator for electric power source of wearable electric devices, two technological elements is needed. The first is approach method that can convert frictional kinetic energy induced by human movement to electric energy in the most efficient way. The second is antibacterial ability to protect itself from foreign contaminant and low toxicity to human skin since it will be used in contact with skin.

Joint research team of Professor Seongpil An and Professor Ki Hyun Kim synthesized the elm bark extract with skin-nontoxic biodegradation polymer, polycaprolactone (PCL) and developed it into felt composed of nanofiber that has diameter of 100nm (one thousandth of a hair thickness). This natural resource based felt was applied for triboelectric nano-generator material.

The invented natural resource based triboelectric nanogenerator could generate maximum of 80V electric energy per each step during walking or running when applied in shoe inserts, and the antibacterial ability of natural material (elm bark extracts) could resist athlete’s foot germs (Tinea pedis).

Professor An reported, “We developed natural felt composed of microfiber with diameter of 100nm which was created based on world’s best level solution spinning technology owned independently by our lab, considering the thinner fiber gets, the more friction area the felt has.”

Also, Professor Kim said, “The natural material used in this research, elm bark (also known as medicinal herb called Salicis radicis cortex), has been used for Gastrointestinal-related diseases and inflammation relief, diuretic effects. Also, elm bark is known for natural antibacterial material, and this research applied this medicinal herb to triboelectric nanogenerator which expanded applicability range, having a significant implication.”

Lastly, the first author of this research, Ph.D. student, Dogun Park said, “Currently, there are many more problems to be solved for nano-generator to be investigated as future ecofriendly electricity source. I hope this research could suggest new directions for ecofriendly nanogenerator.”

This research was supported by National Research Foundation of Korea Basic Research Project in Science and Technology (2021R1F1A1061404), Medical Research Center (MRC) Project (2019R1A5A2027340), Mid-sized Research Project (2021R1A2C2007937).

▲ Natural Materials based High-efficiency Triboelectrical Nanogenerator