Synergistic Electronic Coupling in Boron/MoSe ₂ Nanocomposite for Ultrafast Breath Recognition and Adaptive Human–Machine Interfaces

In the modern era, humidity sensors have found applications ranging from agriculture and environmental monitoring to healthcare and human–machine interfaces. Here, we report a high-performance resistive humidity sensor based on a boron/MoSe2 nanocomposite synthesized via a solvothermal method. The incorporation of two-dimensional MoSe2 nanosheets introduces abundant hydrophilic adsorption sites and promotes rapid proton transport, while nanostructured boron provides efficient conductive pathways that enhance charge transfer and sensitivity. Along with exceptional static sensing parameters, ultrafast response and recovery times of ∼0.69 and ∼0.64 s, respectively, are one of the critical parameters that help these devices to qualify for respiration monitoring. The proposed sensor shows enhanced sensing performance compared with bare boron nanostructures, which show limited sensing performance. In addition, the sensor functions effectively as a noncontact human–machine interface by detecting fingertip-induced humidity perturbations at millimeter-scale separations. Owing to its simple fabrication, low cost, and compatibility with on-chip integration, the proposed boron/MoSe2-based humidity sensor holds strong potential for next-generation wearable health monitoring systems and noncontact interactive devices.