Guar gum reinforced conductive hydrogel for strain sensing and electronic devices

Abstract

Hydrophobically associated conductive hydrogels got great attention due to their excellent properties like stretchability, energy dissipation mechanism, and strain sensor. But hydrophobically associated hydrogels have poor mechanical properties and time response to external stimuli. To enhance the mechanical properties and response to stimuli, Acrylamide- co-Butyl acrylate/Gum based conductive hydrogels were prepared. SDS works as a cross-linker and micelle-forming agent while NaCl makes hydrogel as conductive. The results show that our % strain sensing reached up to 400 %, and fracture stress and fracture strain reached to 0.5 MPa and 401 % respectively. Besides this, it's having an excellent response to continuous stretching and unstretching multiple cycles without any fracture up to 180 s and an excellent time response of 190 s. The conductivity of the hydrogel was 0.20 Sm^-1. The hydrophobic hydrogels showed a clear and quick response to human motions like finger, wresting, writing, speaking, etc. Interestingly, our prepared hydrogels can detect the mood of the human face. Similarly, the hydrogels were found efficient in bridging the surface of electronic devices with human skin. This indicates that our prepared hydrogels can monitor human body motion and will replace the existing materials used in strain sensors in the near future.

Keywords: Human motion monitoring; Hydrogels; Mechanical strength.