An All-Polyurethane Nanomesh Triboelectric Sensor for Swallowing and Voice Detection

Continuous and non-invasive monitoring of swallowing and voice production is important for healthcare and human-machine interaction, yet remains challenging because the laryngeal region undergoes large deformation and continuous motion. Existing wearable sensors often rely on bulk elastomers or multilayer films that can impose mechanical burden on natural throat motion. Here, we present an all-polyurethane (PU) nanomesh triboelectric sensor that forms a compliant interface above the laryngeal prominence for multimodal monitoring of swallowing and voice. The porous nanomesh interface directly contacts the skin without intermediate gel or bulk layers, preserving breathability and conformal contact. Compared with a representative continuous polydimethylsiloxane film, the nanomesh devices exhibited an approximately 14-fold higher water-vapor transmission rate and required 13% of the mechanical work during laryngeal-prominence-mimicking compression. Heat-press-assisted stabilization maintained the high stretchability of the PU nanomesh while reducing the initial electrode resistance by 85% and suppressing the resistance increase at 30% strain by 80% relative to as-spun nanomeshes. The device detects swallowing-associated laryngeal motion at frequencies of several hertz and voice-related vibrations in the 100-300 Hz range, with an acoustic resonance near 150 Hz. Integrated with a compact wireless module, the platform captured W-shaped swallowing signals corresponding to laryngeal elevation and depression and retained measurable phonation signals under changing neck postures, with signal-to-noise ratios of 9.0-21.4 dB. These results establish a breathable and mechanically compliant nanomesh-based throat interface for multimodal laryngeal sensing.