Wearable biomedical sensors have enabled noninvasive and continuous physiological monitoring for daily health management and early detection of chronic diseases. Among biomedical sensors, wearable pH sensors attracted significant interest, as pH influences most biological reactions. However, conformable pH sensors that have sweat absorption ability, are self-adhesive to the skin, and are gas permeable remain largely unexplored. In this study, we present a pioneering approach to this problem by developing a Janus membrane-based pH sensor with self-adhesiveness on the skin. The sensor is composed of a hydrophobic polyurethane–polydimethylsiloxane porous hundreds nanometer-thick substrate and a hydrophilic poly(vinyl alcohol)–poly(acrylic acid) porous nanofiber layer. This Janus membrane exhibits a thickness of around 10 μm, providing a conformable adhesion to the skin. The simultaneous realization of solution absorption, gas permeability, and self-adhesiveness makes it suitable for long-term continuous monitoring without compromising the comfort of the wearer. The pH sensor was tested successfully for continuous monitoring for 7.5 h, demonstrating its potential for stable analysis of skin health conditions. The Janus membrane-based pH sensor holds significant promise for comprehensive skin health monitoring and wearable biomedical applications.

中文翻译：

---

Janus 膜式可穿戴 pH 传感器，具有吸汗性、透气性和自粘性


可穿戴生物医学传感器为日常健康管理和慢性疾病的早期发现提供了无创、连续的生理监测。在生物医学传感器中，可穿戴 pH 传感器引起了人们的极大兴趣，因为 pH 值影响大多数生物反应。然而，具有吸汗能力、可自粘在皮肤上且透气的舒适 pH 传感器在很大程度上仍未得到开发。在这项研究中，我们通过开发具有皮肤自粘性的 Janus 膜 pH 传感器，提出了解决这一问题的开创性方法。该传感器由疏水性聚氨酯-聚二甲基硅氧烷多孔数百纳米厚的基底和亲水性聚(乙烯醇)-聚(丙烯酸)多孔纳米纤维层组成。这种 Janus 膜的厚度约为 10 μm，可为皮肤提供舒适的粘附力。同时实现溶液吸收性、透气性和自粘性，使其适合长期连续监测，而不影响佩戴者的舒适度。 pH传感器经过测试，成功连续监测7.5小时，展示了其稳定分析皮肤健康状况的潜力。 Janus 基于膜的 pH 传感器对于全面的皮肤健康监测和可穿戴生物医学应用具有重大前景。