Abstract

Switchable magnetic information found in some inorganic materials is the fingerprint of countless technological applications, but poor control over processability and magnetic anisotropicity imposes severe restrictions, calling for advanced techniques. In this talk I will present a new class of stimuli-responsive materials, which combines the actuation potential of liquid-crystalline elastomers (LCE) with the anisotropic magnetic properties of ellipsoidal iron-oxide nanoparticles. The resulting hybrid nanocomposites exhibit unique shape-memory features allowing via simple low-stress deformation the reversible storage of magnetic information, which can be erased at low temperature by heating above the LCE smectic-isotropic transition. To illustrate the applicability of this concept, it will be shown how the magnetic information can be read, for example, by magnetic torque measurements. These new nanocomposites offer the unprecedented possibility of manipulating magnetic properties at control parameters, such as deformation, stress and resetting temperatures, typical of soft materials, opening up new scenarios in micro-actuators, magnetic storage devices, sensors or artificial muscles applications. Reversible magnetic memory stored in LCE nanocomposites, as read by magnetic torque measurements. References J. M. Haberl, A. Sánchez-Ferrer, A. M. Mihut, H. Dietsch, R. Mezzenga, Adv. Mater. 2013, 25, 1787-1791. J. M. Haberl, A. Sánchez-Ferrer, A. M. Mihut, H. Dietsch, R. Mezzenga, Nanoscale 2013, 5, 5548. J. M. Haberl, A. Sánchez-Ferrer, A. M. Mihut, H. Dietsch, R. Mezzenga, Adv. Funct. Mater. In press