Programmable Superparamagnetic Shape-Memory Elastomers

Magnetopolymers are desirable for many applications, including flexible electronics, soft robotics and biomedicine.

We will investigate magneto-elastomeric metamaterial composites with novel magnetic and mechanical properties and functions.

These composites uniquely contain magnetic particles embedded in low-melting-temperature polymer particles inside a continuous elastomer matrix.

Exposing such materials to specific sequences of temperatures, magnetic fields and mechanical deformation allows the unique post-synthesis reprogramming of the magnetic and mechanical stiffness properties.

Building with high-coercivity particles results in a novel superparamagnetism, rotation-induced superparamagnetism, that does not follow the Néel–Arrhenius law. Such materials can be uniquely reprogrammed to a stable ferromagnetic, paramagnetic or antiferromagnetic state.

Using low-coercivity particles will result in a novel shape-memory effect, rotation-induced magnetic shape-memory, with – for soft matter unique - reprogrammable memory state.

Other properties, unique for soft magnetic matter, include a remnant magnetic field, susceptibility, or material stiffness that are reprogrammable after fabrication.

We will explore these properties to create i) generic structural building blocks with properties that can be programmed after their assembly or before use, ii) soft magnetic actuators, and iii) to study fundamental physical phenomena (3D spin-ices and structural pattern emergence).