Abstract：
The continuous, noninvasive monitoring of human blood pressure (BP) through the accurate detection of pulse waves has extremely stringent requirements on the sensitivity and stability of flexible strain sensors. In this study, a new ultrasensitive flexible strain sensor based on the interlayer synergistic effect was fabricated through drop-casting and drying silver nanowires and graphene films on polydimethylsiloxane substrates and was further successfully applied for continuous monitoring of BP. This strain sensor exhibited ultrahigh sensitivity with a maximum gauge factor of 34357.2 (∼700% sensitivity enhancement over other major sensors), satisfactory response time (∼85 ms), wide strange range (12%), and excellent stability. An interlayer fracture mechanism was proposed to elucidate the working principle of the strain sensor. The real-time BP values can be obtained by analyzing the relationship between the BP and the pulse transit time. To verify our strain sensor for real-time BP monitoring, our strain sensor was compared with a conventional electrocardiogram-photoplethysmograph method and a commercial cuff-based device and showed similar measurement results to BP values from both methods, with only minor differences of 0.693, 0.073, and 0.566 mmHg in the systolic BP, diastolic BP, and mean arterial pressure, respectively. Furthermore, the reliability of the strain sensors was validated by testing 20 human subjects for more than 50 min. This ultrasensitive strain sensor provides a new pathway for continuous and noninvasive BP monitoring.
摘要：
连续的,通过脉搏波的准确检测来实现人体血压(BP)的无创监测,对柔性应变传感器的灵敏度和稳定性有着极其严格的要求。在这项研究中,通过在聚二甲基硅氧烷基底上滴注和干燥银纳米线和石墨烯薄膜，制备了一种基于层间协同作用的新型超灵敏柔性应变传感器，并进一步成功地应用于BP的连续监测。该应变传感器具有超高的灵敏度，最大应变系数为34357.2（比其他主要传感器灵敏度提高700％），令人满意的响应时间(~85毫秒)，广泛的奇怪范围（12％），和出色的稳定性。为了阐明应变传感器的工作原理，提出了层间断裂机理。通过分析BP与脉搏传导时间之间的关系可以获得实时BP值。为了验证我们的应变传感器的实时BP监测，我们的应变传感器与传统的心电图-光电容积描记器方法和商用的基于袖带的设备进行了比较，并显示了与两种方法的BP值相似的测量结果。收缩压仅有0.693、0.073和0.566mmHg的微小差异，舒张压,和平均动脉压，分别。此外，通过对20名受试者进行50分钟以上的测试，验证了应变传感器的可靠性。这种超灵敏应变传感器为连续和无创BP监测提供了新的途径。
