Material remembers its shape

Researchers at the Swiss Federal Institute of Technology in Zurich (ETH) and the Paul Scherrer Institute (PSI) have developed a new material with magnetic shape memory. It retains a given shape when it is put into a magnetic field. When the magnetic field is removed, the material automatically returns to its original shape. According to a press release, it is a composite of two components: a silicone-based polymer and small droplets of water and glycerin in which tiny particles of carbonyl iron float.

“With our new composite material, we have taken another important step towards simplifying components in a wide range of applications such as medicine and robotics,” says ETH Zurich and PSI materials scientist Paolo Testa, first author of the study. “Our work therefore serves as the starting point for a new class of mechanically active materials.”

This innovative material could reportedly be used in the field of medicine, for catheters that are pushed through blood vessels to the surgical site in the body during minimally invasive operations. It would enable them to change their stiffness and slide through the blood vessel more easily. In robotics, shape-memory materials could perform mechanical movements without a motor, for example. The material could also be of interest for space exploration, where a kind of tire that inflates or folds up again on its own is in demand for rover vehicles.

The fact that the shape memory of the new material is activated by magnetic fields offers higher force than similar materials. Additionally, it does not react to changes in temperature, which is an advantage for medical applications, in particular.