Hybrid Integrated Photomedical Devices for Wearable Vital Sign Tracking.

In light of the importance of and challenges inherent in realizing a wearable healthcare platform for simultaneously recognizing, preventing, and treating diseases while tracking vital signs, the development of simple and customized functional devices has been required. Here, we suggest a new approach to make a stretchable light waveguide which can be combined with integrated functional devices, such as organic photodetectors and nanowire-based heaters, for multifunctional healthcare monitoring. Controlling the reflection condition of the medium gave us a solid design rule for strong light emission in our stretchable waveguides. Based on this rule, the stretchable light waveguide (up to 50% strain) made of polydimethylsiloxane was successfully demonstrated with strong emissions. We also incorporated highly sensitive organic photodetectors and silver nanowire-based heaters with the stretchable waveguide for the detection of vital signs, including heart rate, deep breathing, coughs, and blood oxygen saturation. Through these multifunctional performances, we have successfully demonstrated that our stretchable light waveguide has a strong potential for multifunctional healthcare monitoring.