Multifunctional flexible strain sensor based on three-dimensional core-shell structures of silver nanoparticles/natural rubber

Conventional wearables may pose a health risk by promoting the growth of bacteria on the skin's surface due to sweating or contamination. Here, a multifunctional strain-sensing composite has been fabricated through the combination of highly elastic natural rubber (NR) with silver nanoparticles (AgNPs), which possess antimicrobial and electrical conductivity properties. A 3D core-shell structure composed of AgNPs and NR microspheres effectively reduces the percolation threshold of the AgNPs conductive network. As a strain sensor, the composite film presents a wide sensing range (0%–970%), an exceptionally high gauge factor (GF) value (59.3), and favorable cycling stability (over 1500 cycles at 50%). Finally, the composite film also exhibits antibacterial and hydrophobic properties, indicating its potential for use in challenging environments.