3D Printable Self‐Sensing Magnetorheological Elastomer

• Published in: Macromolecular materials and engineering 2024-02, Vol.309 (2), p.n/a
• Main Authors: Costi, Leone, Georgopoulou, Antonia, Mondal, Somashree, Iida, Fumiya, Clemens, Frank
• Format: Article
• Language: English
• Subjects: 3D printing; Carbon black; Carbonyls; Compression; Elastomers; Fillers; Magnetic properties; magnetoresistive sensors; Magnetoresistivity; magnetorheological elastomers; Magnetostriction; Mechanical properties; piezoresistive sensors; Smart materials; Styrene; Thermoplastic elastomers; Three dimensional printing
• ISSN: 1438-7492; 1439-2054
• DOI: 10.1002/mame.202300294

Magnetorheological elastomers (MREs) are a category of smart materials composed of a magnetic powder dispersed in an elastomeric matrix. They are characterized by the ability to change their mechanical properties when an external magnetic field is applied, called magnetorheological (MR) effect. When a conductive filler is added to a magnetorheological elastomer, the resulting hybrid filler composite showcases both MR and piezoresistive effects. For such a reason, these composites are referred to as self‐sensing magnetorheological elastomers. In this case, the synthesized self‐sensing magnetorheological elastomers are based on styrene‐based thermoplastic elastomers (TPS), carbonyl iron particles (CIP), and carbon black (CB). The hybrid filler concept using various coated CIP and constant CB content showed that above 25 vol.% CIP the resistivity increased rapidly. This work proposes the first case of a 3D printable self‐sensing magnetorheological elastomer and cyclic mechanical compression and tensile mode analysis at high deformation (up to 20% and 10%, respectively). The results showcase a magnetoresistive change of up to 68% and a piezoresistive change of up to 42% and 98% in compression and tension, respectively. In addition, the magnetostriction of the self‐sensing samples has been characterized to be 3.6% and 5.6% in the case of CIP 15 and 30 vol.%, respectively. Self‐sensing magnetorheological elastomers (MREs) showcase resistive changes induced both by magnetic fields and mechanical loads, on top of magnetic‐dependant stiffening. In this work, it is reported the first case of 3D printable self‐sensing magnetorheological elastomers. The proposed materials are characterized both as a function of a varying magnetic field and mechanical cyclic load, both in compression and tension.