Strategies in the preparation of conductive polyvinyl alcohol hydrogels for applications in flexible strain sensors, flexible supercapacitors, and triboelectric nanogenerator sensors: an overview

Conductive nanocomposite hydrogels for flexible wearable sensors

“…Typically, the performance of conductive nanocomposite hydrogel sensors depends on the nanofillers as well as the polymeric network of the hydrogel, which possess both the properties of the nanofillers and the properties and advantages of the polymeric network. 105 The introduction of nanofillers is sufficient to further improve the mechanical properties of hydrogels and endow them with higher electrical conductivity and other functionalities, such as mechanical, self-healing, and adhesion properties. 106 However, in practical applications, water-rich hydrogels inevitably freeze and evaporate at zero temperature, which greatly affect the practical use of hydrogel sensors.…”

Phytic acid/tannic acid reinforced hydrogels with ultra-high strength for human motion monitoring and arrays

“…The current stage is marked by concerns about resource scarcity and environmental pollution, making biodegradable and biomass materials a research hotspot. 19–21 Polyvinyl alcohol is a commonly used material for synthetic hydrogels, 22 exhibiting good biodegradability and biocompatibility. 23,24 However, pure PVA hydrogels have weak mechanical strength, limited functionality, and poor conductivity.…”

Tough and Strain-Sensitive Organohydrogels Based on MXene and PEDOT/PSS and Their Effects on Mechanical Properties and Strain-Sensing Performance

“…11 The poor mechanical properties, such as low strength and toughness, have significantly restricted the practical application of these hydrogels in wearable electronics and devices, such as strain sensors. 12 Additionally, the water within the hydrogels can evaporate at room temperature and freeze at low temperature, resulting in hardening of the hydrogels, which poses a great challenge to the ability of hydrogels to maintain their desired mechanical properties and conductivity. 13 Therefore, developing conductive hydrogels with high strength, strong toughness, excellent stretchability, satisfactory conductivity, persistent moisture retention, and freeze resistance simultaneously has become the hot topic in this field.…”

“…Due to the high moisture content of hydrogels, most conductive hydrogels are mechanically weak and brittle . The poor mechanical properties, such as low strength and toughness, have significantly restricted the practical application of these hydrogels in wearable electronics and devices, such as strain sensors . Additionally, the water within the hydrogels can evaporate at room temperature and freeze at low temperature, resulting in hardening of the hydrogels, which poses a great challenge to the ability of hydrogels to maintain their desired mechanical properties and conductivity .…”