Wireless sensing of many biomedical parameters of interest at once can provide crucial information about disease or overall health state. However, in current practice, biomedical sensing is most often limited to tracking only a single parameter which is inadequate to monitor the multiple factors and their interplay that influence health or disease state. Although many sensor types are currently available, their miniaturization and integration are greatly limited by the need for many additional discrete components necessary for functions such as data readout, powering, and wireless operation. Consequently, resulting multi-sensor system are complex assemblies with significant bulk that prevent their practical implementation in a wearable format. Compact, wearable multi-sensor systems that operate wirelessly have many potential applications in personalized and preventative medicine and monitoring health. In the proposed project, the reflected impedance wireless sensing technology will be leveraged to develop wearable systems that chronically monitor analytes in sweat and interstitial fluid. Potential applications include the artificial pancreas to achieve tight glucose regulation in diabetics comparable to that of healthy individuals, wound healing monitoring to prevent sepsis and infection, real-time quantification of hydration and exertion in high performance athletes, and heart failure monitoring in patients with cardiovascular diseases. This project will provide training opportunities via research experiences for female and underrepresented minority student researchers. To provider further opportunities for diverse audiences to engage with the research outcomes, educational products such as laboratory demonstrations and exercises will be developed that are suitable for both undergraduate and graduate students.
The goal of this project is to leverage the recent discovery of wireless operation using the reflected impedance principle so that multiple unpowered microsensors can wirelessly communicate data capturing changes in electrochemical impedance. For this effort, we will utilize a core wearable platform consisting of a flexible microcoil, integrated thin film bridge capacitor, and sensing electrodes. An external reader wirelessly linked to the wearable platform completes the system. To advance ultra-compact form factor wireless multi-sensor systems, the major tasks include: (1) advancing the theory of wireless reflected impedance sensing, (2) determining factors that enable maximization of performance, (3) developing general design rules for reflected impedance systems that support multiple sensors, and (4) demonstrating under simulated conditions the wireless sensing of multiple analytes by reflected impedance. For the purpose of demonstration, tailored coatings will be applied to the sensing electrode as needed to achieve selectivity to well characterized markers: glucose, cortisol, and ions. The underlying principle of reflected impedance sensing is generalizable for application to other areas of biomedical sensing, including chronically implanted sensors. Adapting different functional coatings enable impedance-based detection of other analytes relevant to other disease conditions.
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.
