3D-Printable, Durable, and Wearable Poly(vinyl alcohol)/Nanosilicate/Borax Organohydrogel Fibers for Digital Healthcare Devices

Abstract

The growing aging population underscores the urgent need for digital healthcare devices that can continuously monitor health and provide early disease diagnosis, rehabilitation, and timely medical intervention. Herein, robust organohydrogel fibers (OHFs) fabricated through continuous wet spinning using an instantaneous gelation system of poly(vinyl alcohol) (PVA) and borax are described. The incorporation of laponite (LP) imparts shear-thinning behavior to the polymer solution and significantly enhances the durability of the hydrogel by simply mixing it with PVA. The resulting organohydrogel fibers exhibit impressive tensile strength (∼300 kPa) and high strain capacity (up to 600%), thereby making them ideal for soft robotics applications. The use of glycerol and sodium chloride (NaCl) in a coagulation bath endows the hydrogel with antifreezing properties (effective at −30 °C), long-term storage stability (7 days), and high conductivity (4.2 S·m–1). With a linear gauge factor of 1.24 for strains up to 800%, these fibers demonstrate exceptional reliability as wearable strain sensors that can accurately detect human movement. The integration of 3D printing technology opens up a broad range of advanced healthcare device applications and offers significant potential for future developments in digital health.