Laser-induced graphene composites-based standalone stretchable sweat sensing system for remote health monitoring

Inflammation as a defense mechanism in the body is an immune response, which forms the basis of many physiological and pathological processes. However, certain infections can also cause an overwhelming local/systemic inflammatory response, leading to life-threatening diseases. Because of the association between specific cytokines and infectious diseases, there is significant interest in utilizing cytokine levels as an early marker for infection. While blood collection and sample analysis have been applied in current testing for cytokines, they often involve phlebotomy and complex laboratory equipment. Although invasive real-time measurement of small molecules can be achieved with aptamer-based sensors, continuous, non-invasive, and remote monitoring of cytokine levels cannot be accomplished. There is an unmet need to develop wearable devices for non-invasive, continuous monitoring of inflammatory markers to identify at the earliest possible time individuals who are likely to be infected. The non-invasive measurement of biomarkers with ultralow concentrations from the biofluids (e.g., sweat, interstitial fluids) with complex composition requires high sensitivity and selectivity in the sensors, which is challenging to achieve with most existing devices. The need for complex laboratory equipment and the lack of sustained power supplies makes long-term, real-time monitoring elusive. This project will result in a standalone device can simultaneously provide the required properties of high sensitivity/selectivity, wireless measurement, and sustained power supplies. A grand challenge in wearable devices is to achieve non-invasive, long-term, real-time, wireless measurements with high sensitivity/selectivity for diagnostic confirmation and health monitoring. In pursuit of this goal, the research project will investigate a set of foundational laser-induced graphene composite materials, manufacturing approaches, and device problems to shift the current bulky devices or wearable sensors toward standalone stretchable sweat sensing systems for remote real-time health monitoring. The proposed standalone stretchable device systems will distinguish themselves from existing wearable devices in that they possess soft microfluidic electrochemical sensors with enhanced sensitivity/selectivity for real-time synchronous detection of multiple analytes and sustained power supplies for long-term operation. A combined experimental and modeling research program will 1) elucidate the effect of highly porous 3D nanocomposite electrodes functionalized by aptamers on enhanced sensitivity/selectivity, 2) understand the role of Multiphysics design for stretchable devices under mechanical deformations, and 3) uncover the fundamental mechanisms of nanocomposites-based power supplies for enhanced power performance. Through the synergistic integration of research and educational activities, this project will also provide next-generation engineers and scientists with career development opportunities and relevant skill sets to address grand challenges related to bioelectronics for human health. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.