Self-Powered Wireless System for Sleep Apnea Syndrome Self-Management Using π-Conjugated Poly(benzodifurandione)-Based Low-Hysteresis Humidity Sensors and Highly Sensitive Pressure Sensors

Simultaneous respiration and motion monitoring is essential for self-management of sleep apnea syndrome (SAS), enabling feedback-driven exercise therapy and symptom alleviation. However, current home-based systems lack integrated sensing and require external power, limiting personalized rehabilitation. Here, we develop a dual-functional, self-powered sensor system integrating n-type conducting polymer poly(benzodifurandione) (PBFDO)-based humidity and pressure sensors for concurrent respiration and motion tracking. The humidity sensor employs a localized surface dipole disruption mechanism. Specifically, the weak hydrophilicity of PBFDO confines water interactions to the surface, while its doped π-conjugated skeleton ensures efficient lateral charge transport. Adsorbed water forms local dipoles that scatter carriers, disrupt π-π conduction, and increase resistance. This enables simultaneous achievement of low hysteresis (4.5% RH), high resolution (1%), fast response/recovery (30 s), and a wide linear detection range (11-98% RH), ensuring precise respiratory monitoring. Simultaneously, PBFDO serves as an effective filler in triboelectric self-powered pressure sensors. Its π-π stacking and lamellar ordering enhance interfacial charge transfer and mechanical robustness, achieving a high voltage (160 V), power density (125 mW/m²), and <2.5% output deviation over 2000 cycles. Notably, harvested biomechanical energy directly powers the humidity sensor, enabling continuous and compact operation. This IoT-integrated system offers a scalable self-management solution for long-term SAS rehabilitation.