Materials that are able to snap on themselves and then restore the original shape to repeat the movement: this is what some researchers from the University of Massachusetts Amherst have created. There is talk of materials «capable of self-propulsion» in the press release issued on the site of the same American university that imagines possible uses relating, for example, to small robots that could climb a flight of stairs autonomously.
In general, materials able to perform such movements then restore the initial shape can be used in all those sectors where there is a need to generate movement in a sustainable way and therefore those sectors ranging from robotics to the production of toys.
The discovery was made by a team of researchers led by professor of polymer science and engineering Al Crosby, of the College of Natural Sciences at UMass Amherst. The researcher worked with a graduate student in his own group, Yongjin Kim, and visiting researcher Jay Van den Berg, of the Netherlands’ Delft University.
Researchers discovered this important effect during an experiment that saw a strip of gel dry out. During the experiment, they noticed that this elastic gel strip while it was leaking liquid, and therefore drying, tended to move and then shoot. These were quite slow movements but every now and then there is a click that accelerates the strip. These were more rapid and sudden movements that occurred as the liquid evaporated. In studying this effect, the researchers discovered that it was caused by the shape of the material and that the effect itself could be exploited to create materials that could «reset» to continue making their movement and therefore to move, eventually.
According to Crosby, there are also examples of nature in relation to this type of movement and they are plants known as «Venus traps», a species of carnivorous plant that captures insects within structures similar to «jaws».
«Snap instabilities are one way that nature combines spring and a latch and are increasingly used to create rapid movements in small robots and other devices, as well as toys such as rubber poppers (toys in the shape of small rubber domes). that jump by themselves once pressed, ed) ”, explains the researcher.
Notes and insights
- UMass Amherst Researchers Discover Materials Capable of Self-Propulsion | Office of News & Media Relations | UMass Amherst (IA)
- Autonomous snapping and jumping polymer gels | Nature Materials (IA) (DOI: 10.1038 / s41563-020-00909-w)