The research team of Professor Kim Sun-jung from Hanyang University's Division of Electrical and Biomedical Engineering developed a 'unipolar artificial muscle' with a U.S. based research team from Texas University and other multi-national research teams. The muscle holds power that is at most three times stronger than the artificial muscle of before.

The newly developed artificial muscle overcame the critical point of prior carbon nanotube material that is used, which is expected to affect researches on high-performance artificial muscles. The result of the research was introduced on the Science and published on the 29th.

The co-research team discovered that when ion exchange resin was coated on a carbon nanotube, it allows creating artificial muscle that is faster and stronger.

The prior carbon nanotube artificial muscle had limitations on its performance by showing bipolar movements within the limited voltage range. Also, due to the electrochemical principle, the range of movements would decrease as its speed increased. On the other hand, the carbon nanotube artificial muscle that is coated with ion exchange resin allows for operation on every voltage range due to its monopolar movements and also creating stronger power as its movement speed increased. The research team of Professor Kim, who is also the co-author of this research paper, analyzed the operation principle of artificial muscle and contributed to the development of cloths impregnated artificial muscle. This opened its possibility on the application on the wearable area also.

The principle of creating self-generated energy using artificial muscle is also expected to be used continuously in developing and researching high-performance artificial muscle. The Hanyang University team also created an artificial muscle that is cloth impregnated with the form of a yarn, showing its possible to be sued as smart-clothing. This research was conducted as the part of Leader Research Support Project that was supported by the Ministry of Science and ICT.

Meanwhile, using the self-generating energy principle that they have announced on Science in 2017, Professor Kim's team had discovered the changing phenomenon of the potential of zero charge (PZC), which is the reason for polar and monopolar movements of the artificial muscle. 

※ Vocabulary:
1) ion exchange resin: a high molecule that works as the medium for ion exchange
2) monopolar movement: movement of two different conditions appearing at the same voltage polarity.
3) polar movement: movement of two different conditions appearing at different voltage polarities.
4) potential of zero charge, PZC: potential where the total of surface charge becomes 0.