Environmentally stable and multi-functional conductive gelatin/PVA/black wattle bark tannin based organogel as strain, temperature and bioelectric sensor for multi-mode sensing.

Conductive hydrogels are regarded as ideal candidates for the application of flexible sensors owing to their excellent flexibility, portability and conductivity. However, it is still challenging and meaningful to prepare multifunctional (self-healing, adhesion, anti-freezing, biocompatibility, antibacterial and conductivity properties) and multi-mode sensing hydrogel-based sensors. Herein, we developed an environmentally stable and multi-functional conductive organogel via dynamic crosslinks based on biomass materials gelatin, black wattle bark tannin and PVA in the propylene glycol/water binary solvent system. Thanks to the dynamic interactions in the system, the good mechanical strength and self-healing performance of the obtained organogel are simultaneously realized. Meanwhile, the organogel integrates many crucial properties such as adhesion, environmental stability (anti-freezing and water retention), biocompatibility, antibacterial behavior and conductivity capacity. Significantly, the organogel can be assembled as three-mode sensors for strain, bioelectricity and temperature sensing. This three-mode sensor can effectively monitor human health data, resulting in providing supplement human health information and conditions. This work displays an interesting approach to construct an intelligent multi-functional conductive biomass organogel based multi-mode flexible sensors.