Versatile hydrogel-based sensor platform for multi-modal mechanical and optical signal detection

This study introduces a versatile hydrogel-based sensor platform capable of detecting and quantifying mechanical impacts, ultraviolet (UV) intensities, and infrared (IR) levels. The sensor, composed of polyvinyl alcohol (PVA), borax, polyacrylic acid (PAA), ferric chloride (FeCl 3 ), and polydopamine (PDA), exhibits tunable mechanical properties and multi-modal responsiveness. It achieves precise mechanical impact detection, with resistance changes from 3.16% for impacts of 6.43 × 10 −5 J to 23.01% for 9.19 × 10 −3 J, supported by an R 2 value of 0.999 0. For UV sensing, Fe 3+ reduction results in resistance changes from −1.21% ± 0.19% at 0.15 mW cm − 2 to −5.9% ± 0.23% at 1.32 mW cm − 2 ( R 2 = 0.988 8). IR detection, driven by PDA′s photothermal effect, shows resistance changes from −1.27% ± 0.23% at 0.410 mW cm − 2 to −8.75% ± 0.26% at 1.083 mW cm − 2 ( R 2 = 0.962 8). By integrating these capabilities into a flexible, durable platform, the sensor demonstrates broad applicability in safety testing, environmental monitoring, and wearable technologies. This multifunctional approach advances sensor technology, offering enhanced precision and adaptability for diverse industrial and environmental systems.