New silicone polymer-based composite with shape memory activated by magnetism

Researchers at the Paul Scherrer Institute and ETH Zurich have developed a new material which has a shape memory activated by magnetism.

The material, a composite material consisting of two components, retains a given shape when it is put into a magnetic field.

Unlike previous shape-memory materials, it consists of a polymer and droplets of a so-called magnetorheological fluid embedded in it.

Areas of application for this new type of composite material include medicine, aerospace, electronics, and robotics.

So far, comparable materials have consisted of a polymer and embedded metal particles.

Instead, researchers at PSI and ETH Zurich used droplets of water and glycyrin to insert the magnetic particles into the polymer.

In this way, they produced a dispersion similar to that found in milk, where fat droplets are dispersed in an aqueous solution.

Similarly, the droplets of the magnetorheological liquid are finely distributed in the new material.

Laura Heyderman, head of the Mesoscopic Systems Group at the PSI, said: “Since the magnetically sensitive phase dispersed in the polymer is a liquid, the forces generated when a magnetic field is applied are much larger than previously reported.”

“This new material concept could only come about through teamwork between groups with expertise from two completely different areas, magnetic and soft materials.”

Paolo Testa, ETH Zurich and PSI materials scientist, said: “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.”

“Our work therefore serves as the starting point for a new class of mechanically active materials.”