Electrical and Electronic Engineering and Information Systems, The University of Tokyo, Tokyo, Japan.
Center for Emergent Matter Science, RIKEN, Saitama, Japan.
Nat Commun. 2021 Apr 14;12(1):2234. doi: 10.1038/s41467-021-22558-6.
Ultraflexible optical devices have been used extensively in next-generation wearable electronics owing to their excellent conformability to human skins. Long-term health monitoring also requires the integration of ultraflexible optical devices with an energy-harvesting power source; to make devices self-powered. However, system-level integration of ultraflexible optical sensors with power sources is challenging because of insufficient air operational stability of ultraflexible polymer light-emitting diodes. Here we develop an ultraflexible self-powered organic optical system for photoplethysmogram monitoring by combining air-operation-stable polymer light-emitting diodes, organic solar cells, and organic photodetectors. Adopting an inverted structure and a doped polyethylenimine ethoxylated layer, ultraflexible polymer light-emitting diodes retain 70% of the initial luminance even after 11.3 h of operation under air. Also, integrated optical sensors exhibit a high linearity with the light intensity exponent of 0.98 by polymer light-emitting diode. Such self-powered, ultraflexible photoplethysmogram sensors perform monitoring of blood pulse signals as 77 beats per minute.
由于其出色的人体皮肤适应性，超灵活光学器件在下一代可穿戴电子产品中得到了广泛应用。长期健康监测还需要将超灵活光学器件与能量收集电源集成，以实现自供电。然而，由于超灵活聚合物发光二极管的空气操作稳定性不足，超灵活光学传感器与电源的系统级集成具有挑战性。在这里，我们通过结合空气稳定聚合物发光二极管、有机太阳能电池和有机光电探测器，开发了一种超灵活自供电有机光系统，用于光电容积脉搏波监测。采用倒置结构和掺杂的聚乙二胺乙氧基层，超灵活聚合物发光二极管在空气中运行 11.3 小时后仍保留初始亮度的 70%。此外，集成的光学传感器与聚合物发光二极管的光强度指数为 0.98 具有很高的线性度。这种自供电的超灵活光电容积脉搏波传感器可监测每分钟 77 次的血液脉冲信号。
