• • Photonic sintering of LbL-assembled Ag nanofilms yields a conductivity of 5.1×10^4 S cm^-1, comparable to bulk silver (6.3×10^5 S cm^-1) and significantly higher than typical solution-processed composites (<10^3 S cm^-1), enabling low-voltage operation and simplified readout circuits for wearable sensors.
• • On oxygen plasma-treated PDMS, the Ag nanofilms exhibit gauge factors exceeding 3000 at strains below 5%, surpassing state-of-the-art crack-based sensors (GF ~2000 at 2% strain) and offering a 50% improvement in sensitivity for detecting subtle biomechanical signals such as pulse waves and sound frequencies.
• • On (3-aminopropyl)triethoxysilane-modified PDMS or thermoplastic elastomers, the films sustain stretchability up to 50% strain with small resistance variations (ΔR/R0 < 10%), providing a dual-mode sensing platform that can be tuned for either high sensitivity or high stretchability by substrate engineering.
• • The substrate-dependent electromechanical properties arise from differences in interfacial adhesion and crack propagation: oxygen plasma treatment creates strong covalent bonding that promotes controlled crack opening, while APTES modification yields weaker van der Waals interactions that allow sliding and strain accommodation, as confirmed by finite element analysis and in situ crack observations.