Nanomaterials-enhanced, stretchable, self-healing, temperature-tolerant and adhesive tough organohydrogels with long-term durability as flexible sensors for intelligent motion-speech recognition

Abstract

Conductive hydrogels are flexible artificial materials that are promising for a broad range of applications such as wearable sensors for healthcare and exercise monitoring, electronic skins and soft robotics. However, conventional hydrogels are inevitably confronting several limitations on service life, long-term stability, and usability in extreme environments. Herein, a temperature-tolerant (-30 ∼ 60 °C), stretchable (3734 %), adhesive (220 kPa at porcine skin), self-healing and conductive tough organohydrogel is facilely developed through in situ free radical polymerization followed by glycol solvent replacement for flexible strain sensors. The organohydrogel-based sensor exhibits excellent reliability and a wide sensing range (5 %-1500 %) to precisely monitor human joint movements, wrist pulses, micro-expressions and vocal signals. Besides, the excellent mechanical and electrical properties of the obtained organohydrogel could be retained even after being treated under harsh environment (-30 °C for 24 hrs/60 °C for 96 hrs) or stored in ambient condition for up to 60 days. Furthermore, the organohydrogel could be integrated within a throat patch and wristband for exercise guidance based on its excellent sensing performances on both voice and postural recognitions in real time, which is envisioned to correct posture and improve the training effects of athlete. Thus, the developed organohydrogel sensor holds great promise as wearable devices for intelligent speech-motion recognition, rehabilitation training and human–computer interaction.