Dual-network sodium alginate/polyacrylamide/laponite nanocomposite hydrogels with high toughness and cyclic mechano-responsiveness

Abstract

Ionic conductive hydrogels with good mechanical strength and toughness have arisen a heated debate for their prospect in the fields of human motion sensors, sensory skins, and personal healthcare diagnosis. Nevertheless, the probable candidates rarely manage to meet the mechanical requirements to be used as wearable devices. As possible solutions, the dual network (DN) structure and nanocomposites (NC) have been adopted, respectively. Still, it is highly favorable yet challenging for the single DN or NC to design a hydrogel with toughness, high strength, stretchability, and fatigue resistance for potential applications. Herein, we combined the two commonly used strengthening strategies to prepare the sodium alginate/polyacrylamide/Laponite hydrogels (SPL hydrogels). The designed ionic conductive SPL hydrogels exhibited good mechanical properties, such as tensile strength and stretchability of up to ~206 KPa and ~854%, respectively, compressive strength of up to ~2136 KPa (90% strain), and high toughness (~134.78 kJ/m3). Besides, the designed ionic conductive hydrogels also possessed stable and timely mechano-responsive performances along with relative resistance changes (RRCs). It is envisioned that the designed high strength and toughness hydrogels may be promising for applications as bio-sensors and personal healthcare diagnoses.