Development of Dual-Function Microelectronic Fibers for pH and Temperature Sensing: Toward <i>In Vivo</i> and Wearable Applications

Temperature plays a crucial role in biological functions in normal physiological and pathological states and is intricately linked with chemical dynamics <i>in vivo</i> at the cellular, circuit, and system levels. Despite advances in temperature measurement technologies for internal monitoring, systems capable of simultaneously tracking localized temperature and chemical changes are still underdeveloped. In this study, we introduce dual-sensing hybrid fibers with a miniature footprint of <400 μm in diameter, fabricated using the thermal drawing process. These fibers exhibit precise temperature sensitivity, detecting changes as small as 0.5 °C, and demonstrate highly sensitive and reversible pH detection, a critical physiological parameter. Furthermore, through laser micromachining and surface functionalization, we highlight the potential of these fibers for wearable applications in dual pH and temperature sensing. This innovative dual-sensing technology offers a versatile platform for probing temperature and chemical signaling <i>in vivo</i> and wearable applications, with significant implications for therapeutic development and a deeper understanding of biological processes in various environments.