Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis

Abstract

Wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual's state of health1–12. Sampling human sweat, which is rich in physiological information13, could enable non-invasive monitoring. Previously reported sweat-based and other non-invasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state14–18. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanically flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This application could not have been realized using either of these technologies alone owing to their respective inherent limitations. The wearable system is used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and to make a real-time assessment of the physiological state of the subjects. This platform enables a wide range of personalized diagnostic and physiological monitoring applications.

Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform

“…Despite significant progress made in printed and flexible biosensors in the field, a majority of wearable devices focus on monitoring of physical activity or selected electrophysiological parameters, providing only limited information regarding physiological changes of complex homeostatic responses (4)(5)(6)(7)(8)(9)(10). Wearable chemical sensors offer great opportunities for collecting physiological information at the molecular level (3,(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Recently research advances have resulted in a variety of wearable sweat sensors that can be used for real-time analysis of sweat biomarkers including electrolytes, metabolites, and heavy metals (11)(12)(13)(14)(15)(16)(17)(18)(19)(20).…”

Photopatternable PEDOT:PSS/PEG hybrid thin film with moisture stability and sensitivity

“…With increasing awareness and demands regarding personalized health care, wearable sensors have been extensively investigated in recent years, for which electrical conductance, mechanical flexibility, chemical stability, optical transparency, and biocompatibility are all required [52][53][54][55][56] . The conductive PEDOT:PSS film has proven to be a candidate material for such wearable applications 57,58 .…”

Simultaneous Monitoring of Sweat and Interstitial Fluid Using a Single Wearable Biosensor Platform

“…At the same time, wearable devices should monitor interesting and/or actionable parameters, and thus, significant research activity has augmented the measurement of vital signs and motion with the monitoring of biochemical markers 4, 5, 6, 7, 8. Recent efforts have focused on epidermal biomonitoring systems of two readily obtainable biofluids: skin interstitial fluid (ISF)9, 10, 11, 12 and sweat 13, 14, 15, 16, 17, 18, 19. Reliable and convenient noninvasive monitoring of target biomarkers in these biofluids can potentially have a major impact on a wide variety of healthcare and wellness applications.…”