Printed Wearable Electrochemical Sensors For Healthcare Monitoring

With an expected compound annual growth rate of 35% over the next five years, the global wearables market is poised to reach 148 million annual shipments in 2019. One of the alluring factors of wearables is the incorporation of sensors that can monitor a people's well-being and their surroundings in a continuous autonomous fashion. Such continuous stream of vital data thus offers unprecedented avenue in healthcare, defense and environmental domains. Though the attractiveness of wearable sensors is indubitable, this nascent field is marred with several challenges and not much has been done to address these. A major challenge is the unavailability of important wearable sensors. For example, the wearable sensor field is dominated by sensors that monitor physical parameters, for example, motion, pressure, temperature, heart rate and brain-activity sensors etc. One must monitor chemicals in addition to physical parameters in order to obtain a comprehensive knowledge of a person's well-being. Continuous chemical monitoring is important for analyzing fitness levels, alerting people about serious medical conditions, e.g., diabetes, traumatic brain injury, soft tissue injury etc. At present only blood analyzers are available to measure these chemicals. But the intrusive nature of these analyzers, due to blood sampling step, render then impractical for continuous, everyday use. Sensors that can perform continuous non-invasive monitoring of vital chemical biomarkers are thus highly desired, yet missing. The present thesis focuses on filling this technological vacuum by developing body-compliant, skin-worn electrochemical sensors that can detect physiologically relevant chemicals directly on the human skin in a completely non-invasive fashion.