Biphasic Conductive Inks & Organogels for Soft Machines and Bioelectronics

Abstract

Over the past decade, there's been tremendous advancements in soft and highly stretchable circuitry for use in epidermal electronics for health monitoring, wearable computing, and soft robotics. As these technologies continue to improve, there is increasing interest in new material architectures that allow these materials to be printable over large areas or to exhibit robust self-healing properties. Here, I present progress on new classes of highly elastic “biphasic” composites that incorporate gallium indium (EGaIn) liquid metal and silver flakes within a soft polymer matrix. These include printable inks for creating soft, sticker-like, digital circuits and bioelectronic interface using styrene-isoprene-styrene (SIS) thermoplastic elastomer as the polymer binder. I also present recent progress on EGaIn-Ag-organogel composites that exhibit unique combinations of dynamically tunable electrical conductivity and spontaneous mechanical self-healing. These composites can be utilized for applications that range from highly stretchable digital circuits to bioelectronic stickers for electrophysiological monitoring.