10. Multifunctional Epidermal Sensor Systems with Ultrathin Encapsulation Packaging for Health Monitoring

Wearable sensors have the potential to enable longitudinal, objective health monitoring in patients with chronic diseases, including cardiac rhythm disorders, neurological and movement disorders, diabetes, and pain. However, conventional wearable devices are typically comprised of rigid, packaged electronics, which may compromise overall signal fidelity and wearer comfort during activities of daily living and sleep. In this chapter, we present recent advances in the development of thin and stretchable epidermal systems for biometric data measurements. These non-invasive epidermal systems are fully integrated with multiple sensors, an analog front end module, a radio for wireless communication, onboard flash memory, a rechargeable battery all encapsulated in a soft, stretchable and water-resistant silicone, and with an air permeable adhesive layer that interfaces with the human skin.  The encapsulated system intimately couples with the skin at multiple locations on the body. We present results showing the potential of this technology to quantitatively assess bio-kinematics and electrophysiological signals. Finally, we provide perspectives on remaining challenges and opportunities to achieve clinical validation and commercial adoption of these technologies.