LAUSR

Liquid metal embedded elastomers (LMEEs) are highly stretchable composites comprised of microscopic droplets of eutectic gallium-indium (EGaIn) liquid metal embedded in a soft rubber matrix. They have a unique combination of mechanical, electrical, and thermal properties that make them attractive for potential applications in flexible electronics, thermal management, wearable computing, and soft robotics. However, the use of LMEEs in direct contact with human tissue or organs requires an understanding of their biocompatibility and cell cytotoxicity. In this study, we investigate the cytotoxicity of C2C12 cells in contact with LMEE composites composed of EGaIn droplets embedded with a polydimethylsiloxane (PDMS) matrix. In particular, we examine the influence of EGaIn volume ratio and shear mixing time during synthesis on cell proliferation and viability. We also examine the special case of electrically-conductive LMEE composites in which a percolating network of EGaIn droplets is created through "mechanical sintering." This study in C2C12 cytotoxicity represents a first step in determining whether LMEE is safe for use in implantable biomedical devices and biohybrid systems. This article is protected by copyright. All rights reserved.