Highly Conductive and High-tensile Methacrylated Hyaluronic Acid Hydrogels for Strain Sensing Applications
摘要
Owing to their good biocompatibility, polysaccharide hydrogels have broad application prospects in the field of flexible strain sensors. However, there are still significant challenges in the preparation of polysaccharide hydrogels with good mechanical properties. MCA-LiCl hydrogels were prepared by introducing methacrylated hyaluronic acid (MeHA) into the polymer network in the presence of acrylic acid (AA), acryloyloxyethyltrimethyl ammonium chloride (CATAC), and metal ions. The polymer network not only has a chemically cross-linked network and a tough network structure, but also benefits from a variety of supramolecular interactions, such as hydrogen bonding and coordination covalent bonding, resulting in excellent mechanical properties, with an elongation at break of 1390%, a tensile strength of up to 1200 kPa, a toughness of 9.4546 MJ/m3, and adhesive properties towards various substrates. At the same time, the hydrogel has a high conductivity (5.33 mS/cm) and high strain-sensing sensitivity (Gauge factor=2.55). The flexible strain sensor assembled from the prepared MCA-LiCl hydrogel can be used to detect human movements, from micro-expressions (smiles, swallowing) to pulse signals and other physiological activities, as well as large-scale joint movements (wrists, elbows, knees, fingers, etc.), realizing the real-time monitoring of full-scale human movements. The prepared hydrogels have potential applications in wearable devices, electronic skin, and strain-sensor components.