Soft wearable piezoelectric sensors based on PZT/SMPU composites for monitoring small arteries

• The proposed soft piezoelectric sensors, PZT/SMPU sensors, perform high sensing resolution of 0.05 Pa/5 µm. • The PZT/SMPU sensors show high resistance to motion artifacts, ensuring accurate pulse monitoring during large motion. • Realize the continuously monitoring of typical pulse waves from small arteries. • Distinguish the state changes of small arteries clearly. Cardiovascular disease begins with pathological changes in small arteries, and early diagnosis is crucial for improving prognosis and preventing severe complications. However, continuously monitoring the small arteries is still a challenge due to the limited accuracy of soft wearable sensors. To observe the pulse waves of the small arteries, this work develops soft wearable piezoelectric sensors based on PZT/SMPU composites. The sensing resolution of about 0.05 Pa / 5 µm, combined with a sensitivity of about 2.2 mV/Pa and a response time of 11.5 ms, makes it possible to detect typical pulse waves of small arteries with tiny features (the tidal waves). Combining with the remarkable resistance to motion artifacts, the PZT/SMPU sensors can monitor the typical pulse waves of the supratrochlear artery, facial artery, fingertip artery and digital artery. Moreover, the measured pulse waves can maintain a typical waveform even during motion. The results supply a promising method which enables the diagnosis of cardiovascular diseases at the early stage.