Independent yet simultaneous sensing of pressure and temperature from nostril airflow for ultrasensitive respiratory monitoring

Accurately detection of nostril airflow is vital for real-time respiratory monitoring. However, the developed methods only rely on single stimulus sensing for nostril airflow, which is extremely susceptible to interference in the complexed environment, and severely affects the accuracy of detection results. Here, a multimodal integrated eutectogel sensor was explored to simultaneously sense the pressure and temperature stimuli of nostril airflow, via independently outputting capacitance and resistance, respectively, yet without cross-coupling. The completely physical crosslinking and the synergistic interaction of HAp and tannic acid (TA) within the network endow this eutectogel with extremely low modulus, remarkable self-healing efficiency, robust adhesion, excellent environmental stability and bio-compatibility. By integrating this synthetic eutectogel with circuit design, a multimodal sensor was developed, which exhibited superior pressure sensitivity to other reported gel-based sensors. As a proof of concept, this sensor was further explored to diagnose a traditional respiratory disease of obstructive sleep apnea syndrome (OSAS) via simultaneously detecting five kinds of stimuli in the sleeping process, greatly improving the accuracy and reliability of the detection results. This work provides a highly effective strategy for achieving ultrasensitive respiratory monitoring and forecasting respiratory diseases.