(181a) Ultra-Robust Gel Hybrids for Epidermal Bio-Monitoring

Gel based sensor for personal health monitoring and human–machine interaction has attracted enormous interests [1-5]. A seamless and tough interface to integrate incompatible/immiscible soft layers is highly desired for flexible/wearable electronics [6]. Here, we introduce a surfactant mediated interfacial chemistry (SMIC) to achieve seamless and tough interfaces in soft multi-layer structures, with an ultra-high interfacial toughness up to ~1300 J/m2 for the architectural gel hybrid (AGH). The reversible interfacial noncovalent interactions effectively dissipate the energy on interface to sustain an excellent durability with ~2% reduction in interfacial toughness after 1000 tensile cycles. This strategy can be universally applied to the hybrid systems with varied interfaces between interior hydrogel (PAA, PVA, PAAm, gelatin) and exterior hydrophobic soft matter (ionogel, lipogel and elastomer). The AGH based mechano-sensor presents remarkable robustness and stability in a wide range of conditions, i.e. open air, underwater, various solvents and temperatures. Epidermal bio-monitoring, tactile trajectory and facial expression recognition are demonstrated using the AGH sensor in various environments. A rich set of electrophysiological signals are acquired with robust and excellent quality.