Pulse sensor based on single-electrode triboelectric nanogenerator

A pulse sensor based on single-electrode triboelectric nanogenerator is reported in this work. The device has simple device structure: a PET film with ITO coating layer stacking with a thin polydimethylsiloxane (PDMS) film with a trench structure. The surface of PDMS film is negatively charged through triboelectric effect with the acrylic mould. The typical human pulse presenting the radial artery pressure wave is successfully extracted from the output pulse signal. The incident wave and two reflected waves are clearly shown in the output signal. The radial artery augmentation index AIr and the time difference between two peaks ΔTDVP used to diagnose arterial stiffness are gained and they are consistent with the typical medical value. The correlation between the structure parameters and the output signal is studied and the optimal geometry is obtained. The stability of the device is verified in a cycling test after 2500 press-and-release operations. The simple device structure is very convenient for its integration into a wearable electronic device. The pulse sensor in this report may find application in medical monitoring and wearable electronic products in the future.