All-nanofiber–based, ultrasensitive, gas-permeable mechanoacoustic sensors for continuous long-term heart monitoring

Significance We have fabricated an all-nanofiber–based mechanoacoustic sensor that exhibits an acoustic sensitivity as high as 10,050.6 mV Pa −1 in the frequency range of 10 to 500 Hz. The sensors are ultralightweight (total weight 5 mg or less) and gas-permeable. These superior performances enable our sensors to continuously measure the mechanoacoustic heart signals for longer periods (>10 h) with an extraordinarily high signal-to-noise ratio of 40.9 decibels.