A new type of plastic that makes muscles flex

Robots are becoming more and more human-like. So-called biomimetics transmit natural processes to machines. In the future, a robot could be powered in part by a muscle-like substance rather than hydraulic means or a myriad of electric actuators. The technology could then flow into soft robotics systems, which could also be suitable for prosthetics based on human biology.

strong muscles

Researchers at Stanford University in California are now pursuing such an idea. ocean team Zinan Bao From the Institute of Chemical Engineering he created a plastic material with remarkable properties. It is a shape memory polymer that can store and retrieve energy. After deformation, which includes both pulling and bending, these materials return to their original position by applying certain parameters. This can be light, but also heat, As explained by Bao and Co. With a simple hair dryer.

The Problem: So far, plastics like this have been rather weak in terms of energy storage and re-release. It is now reported that the latest material from the Stanford team is It can absorb nearly six times more energy than previous similar variantsThey also wrote in a research paper in the American Chemical Society’s ACS Central Science.

Huge energy effect

Bao and her team achieved the new quality of energy storage by inserting specific units of methylenediphenylurea into an existing polypropylene glycol backbone. The storage effect is created by reshaping the contained polymer chains, which form hydrogen bonds between urea groups when deformed. The bonds are again destroyed by heat, allowing to return to their original state – with the aforementioned high energy effect (17.9 joules / g). In the experiment, the polymer can be stretched to five times its length.

According to the calculations of Bao & Co. , the material can lift the weight of objects 5000 times when heated. In a demonstration, a wooden doll’s polymer was used as a “muscle” and he showed how she can bend the arm at the elbow. The materials should also be inexpensive and easy to manufacture. Practical applications are currently under consideration.

(Bachelor’s)