Machine-learning-enabled starch/MXene moisture sensing bioelectronics for human monitoring and interaction

The drive toward sustainable sensors demands materials and manufacturing routes that deliver high sensing performance without generating persistent waste. We report a water-based, blade-coating process to fabricate starch/Ti 3 C 2 Tₓ MXene nanocomposite films that operate as multifunctional, moisture-responsive bioelectronics. The films form a layered conductive architecture with a Young's modulus of 6.4 GPa and tensile strength of 82.3 MPa at only 1.36 vol% MXene, exceeding the mechanical performance of previously reported biodegradable conductive films. The composite films display a low percolation threshold of 0.48 vol% and offer tuneable conductivity over 9.6 × 10 −4 to 0.48 S/m. In combination with exceptional humidity sensitivity (>700% ΔR/R 0 at 95% RH), these features enable high-performance multimodal moisture sensing, including respiration analysis, speech detection, skin hydration monitoring, and non-contact human–machine interaction (HMI). When integrated with machine-learning classification, a single transient sensor can accurately distinguish breathing patterns and recognise spoken words with 97% accuracy. In addition, the films exhibit moisture-driven actuation, excellent biocompatibility (cell viability >97%), and fully biodegrade in soil within 30 days. By combining scalable processing, intelligent sensing and transient functionality, this work positions biodegradable bioelectronics as a credible alternative to conventional wearable sensor technologies. • We demonstrate, for the first time, that humidity-induced resistance signals from natural-biopolymer based, transient films can be processed using machine learning to accurately classify breathing modes and spoken words, enabling AI-assisted physiological monitoring and HMI. • The biobased nanocomposite films exhibit exceptional humidity sensitivity (>700% ΔR/R₀ at 95% RH), enabling precise detection of moisture variations for respiration monitoring, speech recognition, skin-hydration assessment, and contactless control of a smart-car. • In addition, the films combine a low percolation threshold (0.48 vol%), tuneable conductivity, and high mechanical strength (82.3 MPa), ensuring stable electrical performance and mechanical integrity during repeated operation. • The devices fully biodegrade in soil within a month, addressing the rapidly growing challenge of electronic waste from disposable sensors and short-lifetime wearables.