The research group of Takuzo Aida, Group Director of RIKEN (also serving as a professor at the University of Tokyo) and Takayoshi Sasaki, Fellow of the National Institute for Materials Science, has succeeded in developing a hydrogel that moves like muscle.Hydrogel is a jelly-like substance that loses its fluidity by trapping water molecules between mesh-like substances, and is likely to be much closer to the realization of artificial muscles.
Traditional power sources include motors and hydraulics made of metal.These are suitable for large-scale work.On the other hand, in factories and medical / rehabilitation sites, there is a demand for a power source with light and soft characteristics to assist human work.Artificial muscles made from hydrogel are attracting attention as candidates to realize such power.However, conventional hydrogels have problems such as slow operation and limited use in water.
In this research, we created a sandwich-like structure in which hydrogel is sandwiched between sheets that repel static electricity.By changing the state of hydrogel by external stimulus, we thought that the entire structure could be expanded and contracted by increasing or decreasing the repulsive force between the sheets.In this study, we chose a hydrogel whose affinity with water changes depending on the temperature.When the affinity with water decreased due to heating, the repulsive force between the sheets increased, and it stretched to 1 times the length in just 1.7 second.Furthermore, it was confirmed that when this is cooled, it also shrinks to its original length in 1 second.Furthermore, it became clear that the total volume was kept constant during this expansion and contraction.This means that it works in any environment except underwater, as there is no need to move water in and out when expanding and contracting.
This has greatly brought us closer to the realization of high-quality artificial muscles.In addition, the operating principle itself is unprecedented as a power source using molecules, and it seems to have a great impact on future related research.
