Low Operating Voltage and Highly Pressure-Sensitive Printed Sensor for Healthcare Monitoring with Analogic Amplifier Circuit

Flexible printed analogic amplifier circuits are required in wearable sensors to enhance their sensitivity for application in various fields such as healthcare, artificial skins, and soft robotics. Various technologies have been proposed to develop wearable sensors for healthcare. However, the development of piezopolymer-based printed healthcare devices for monitoring human vital signs that simultaneously achieve high sensitivity and low operating voltage remains a challenging task. Here, a highly pressure-sensitive printed sensor with low operating voltage is demonstrated and applied to monitor human pulse wave velocity (PWV). The printed sensor consists of a 2 μm thick pressure detector and an organic analogic amplification circuit that are simultaneously formed on flexible substrates. The printed organic analogic circuit can amplify the generated signal by a gain factor of 10. This configuration makes it possible to combine good pressure sensitivity (∼10 kPa) with a low operating voltage of −3 V. We attached the sensor on the skin to efficiently monitor human vital signs using PWV to estimate health conditions.