Electret-based wrist-worn pressure sensor for non-invasive monitoring of pulse and blood pressure

As cardiovascular diseases increasingly threaten human lifespan, developing wearable devices for continuous blood pressure (BP) monitoring is crucial for early diagnosis. Here, we report an electret-based wrist-worn pressure sensor (EWPS) featuring facile fabrication, superior flexibility, and high sensitivity, thereby developing a pulse- and BP-monitoring system with only one EWPS for measurement. The sensor has achieved an elastic modulus of 11.62 kPa—comparable to that of human skin, a high sensitivity of 3.86 V kPa⁻¹, a minimum detection limit of 3.8 Pa, and an ultra-short response time of 20 ms. Moreover, the BP values measured with our monitoring system demonstrate mean errors within ±5 mmHg compared to those obtained with an OMRON wrist-type BP monitor, showing promise for non-invasive in-home monitoring of pulse and BP for early diagnosis of cardiovascular diseases and other hypertension- or arrhythmia-induced conditions.