Room temperature synthesis and hydrophobic surface protection of silver dendrites for hydrogel stretchable sensors

Abstract

Hydrogel stretchable sensors have gained increasing popularity as essential components for next-generation flexible electronics. Stringent standards have been placed on the cost, conductivity, stability, and sensitivity of composites. In this work, highly conductive silver dendrites with uniform morphology were successfully synthesized by galvanic displacement reaction. Due to the more complex three-dimensional structure of the silver dendrites, the percolation threshold of the conductive composites was reduced to approximately 45 wt%. By decorating the as-prepared silver dendrites with a dense and hydrophobic dodecanethiol layer, the issue of hygrothermal stability in the hydrogel matrix has been successfully addressed. Silver dendrites conductive composites exhibited excellent electrical conductivity (8.57×10−4Ω∙cm for 65 wt% silver dendrites) and sensing properties. The stretchable conductors exhibited high sensitivity and linearity with F= 9.48 and R2= 0.9967. Therefore, human-computer interaction was successfully carried out by monitoring the movement of fingers, wrists, elbows, and knees of the human body.