(467a) Highly Conductive, Stretchable, and Biocompatible Nanocomposite for Electromechanical Cardioplasty

Intrinsically stretchable conductors form a vital component of advanced soft bioelectronic devices. And novel nanocomposites based on conductive nanomaterials have been used in diverse applications of implantable and wearable bioelectronics. Among many nanomaterials for the composites, silver nanowires (Ag NWs) have been popular. However, achieving highly conductive and soft composites simultaneously is challenging. Because bioelectronics is necessarily exposed to biofluids, preventing Ag NW oxidation and Ag ion leaching is a significant challenge. Here we have achieved a highly conductive, biocompatible, and soft nanocomposite by using silver-gold (Ag-Au) core-sheath NWs and polystyrene-butadiene-styrene (SBS) elastomer. We synthesized ultralong Ag NWs encapsulated with a smooth and uniform Au sheath and then mixed them with the polymer. Phase separation of Ag-Au NWs and SBS occurs, which forms microstructures in the composite, reduces Young’s modulus, and increase softness and conductivity of the composite. We used the nanocomposite to fabricate a customized multi-channel soft cardiac mesh for mapping the diseased swine heart epicardially and applying customized feedback stimulation therapy. The global resynchronization therapy based on the multichannel pacing improved the pumping capability of the animal heart dramatically.