Wearable biosensors are considered to be a promising technology that revolutionizes conventional health monitoring methods as it is able to provide precautions when potential health problem is detected. However, the current fatigue-monitoring methods are still using either invasive blood tests or bulky inconvenient devices. Herein, we present a new skin patch sensor based on porous Ultra-High-Molecular-Weight Polyethylene (UHMWPE) nanomembranes which tracks muscle fatigue through sweat biomarkers, particularly cortisol hormone. By having nano-level thickness (i.e. around 100nm), the sweat sensor is able to conform perfectly to human skin without the necessity of any adhesives. We used Raman spectroscopy to analyze the sweat cortisol in the skin patch, established the calibration curve for both qualitative and quantitative characterization of sweat cortisol level change and validated the measurements with the blood samples collected at the same exercise intensity. From our experimental data, it is concluded that the cortisol level increases as the exercise intensity are increased and a strong correlation between the sweat cortisol and blood cortisol has been proven, demonstrating the patch’s ability to detect sweat cortisol which acts as a strong indicator of sports fatigue level. Our developed UHMWPE membrane opens up a large opportunity for developing a one-of-a-kind sweat sensor by further integrating it with flexible electronics for signal processing and real-time transmission in future work.

中文翻译：

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适用于运动疲劳的全形多孔聚乙烯纳米薄膜汗液传感器

穿戴式生物传感器被认为是一种有前途的技术，它彻底改变了传统的健康监测方法，因为它能够在检测到潜在的健康问题时提供预防措施。然而，当前的疲劳监测方法仍然使用侵入性血液测试或笨重的不便装置。本文中，我们介绍了一种基于多孔超高分子量聚乙烯（UHMWPE）纳米膜的新型皮肤贴片传感器，该膜通过汗液生物标志物（尤其是皮质醇激素）跟踪肌肉疲劳。通过具有纳米级的厚度（即100nm左右），汗液传感器能够完美贴合人体皮肤，而无需任何粘合剂。我们使用拉曼光谱分析皮肤斑块中的汗液皮质醇，建立了汗液皮质醇水平变化的定性和定量表征的校准曲线，并以相同运动强度采集的血样验证了测量结果。根据我们的实验数据，可以得出结论，随着运动强度的增加，皮质醇水平也增加，并且汗液皮质醇和血液皮质醇之间的相关性得到了证明，证明了该贴片具有检测汗液皮质醇的能力，而汗液皮质醇是运动的重要指标疲劳程度。我们进一步开发的UHMWPE膜通过将其与柔性电子器件进一步集成在一起，为信号处理和实时传输提供了广阔的机会，从而可以开发出一种汗液传感器，从而在将来的工作中发挥更大的作用。