MXene-based dual-network conductive organic hydrogel for wearable sensor to monitor human motions

Conductive hydrogel is a novel material that can be used to prepare flexible wearable strain sensors. It paves the way for future uses in electronic skin, human-computer interaction, and personalized medical monitoring. However, because the majority of conductive hydrogels use pure water as their medium, they will freeze at low temperatures. It will inevitably lose water at room temperature. We developed a PAM/SA/MXene organic hydrogel (denoted as PSMOH). First, MXene nanosheets were added as conductive filler into the double network polymer hydrogel, which was composed of polyacrylamide (PAM) and sodium alginate (SA), we denoted as PSMH. And then immerse the prepared PSMH in a glycerol solution using a solvent displacement method to obtain PSMOH. Even if at extreme temperatures (-30 degrees C), the prepared PSMOH has a strong antifreezing ability and can retain moisture for 8 days. The sensor also has excellent mechanical properties (tensile strain is 1579%), self-adhesive property, excellent sensitivity (gauge factor is 49.92), low detection limit (1% strain), and excellent fatigue resistance (800 cycles at 30% strain). As a result, the hydrogel can be assembled into a flexible wearable sensor for real-time monitoring of human motions and other activities.