Piezoelectret Sensor Made From an Electro-spun Fluoropolymer and Its Use in a Wristband for Detecting Heart-beat Signals

We developed a new wearable wristband-type piezo-sensor for detecting the pressure signals from the heartbeat. A piezoelectric porous electret made from electro-spun poly(tetrafluoroethylene) (PTFE) was used as the piezo-sensor material. This lightweight and flexibile porous PTFE electret exhibited high and stable piezoelectricity, enabling the realization of a piezo-sensor in a new wearable wristband-type instrument. Using the instrument, we observed a signal with detection accuracy equal to that of an electrocardiogram.