Multi-modal piezoresistive sensor based on cotton fiber aerogel/PPy for sound detection and respiratory monitoring

At present, most wearable flexible sensors can satisfy the requirements of sensitivity and wide response range. However, how to prepare sensors with good sensing performance and integration functions is still an urgent problem to be solved. Herein, the multimodel piezoresistive sensor integrating sound recognition, airflow detection and respiration monitoring was manufactured by vapor deposition of polypyrrole on cotton fiber aerogel (CA@PPy). The sensor exhibits wide response range (0–122.50 kPa), high stability (over 4500 cycles), high pressure resolution (0.2%) and ultra-light density (27.5 mg/cm3). Besides detecting normal human motion signals, it can also capture biological/abiotic sound signals with excellent sensitivity (minimum detection limit is 56 dB). Moreover, the sensor can also be used to detect the air flow rate with the minimum flow rate of 0.09 m/s, providing real-time respiratory monitoring for patients with respiratory diseases. We believe that this integrated multimode sensor will have great application potential in flexible electronics and bring great convenience to people's lives.