PFI-TT: Flexible Electronic Devices for Harvesting Body Heat toward Self-Powered Wearable Health Monitoring

The broader impact/commercial potential of this Partnerships for Innovation - Technology Translation (PFI-TT) project lies in enabling wearable devices that can be used for remote, vigilant, and long-term health monitoring. The COVID-19 pandemic has recently highlighted the acute need for such devices to manage/protect individual and public health, particularly for those with chronic underlying conditions. Continuous monitoring of multiple biomarkers is one of the key enablers of precision and personalized medicine. However, current products on the market are not capable of providing the medical and scientific community the necessary access to high-resolution and longitudinal data. These systems typically lack multiple sensing modalities while also suffering from short battery life. To address the need, wearable platforms must operate with no interruptions to collect high granularity data over time and establish individual health baselines. This can be accomplished by harvesting the excess energy from the human body and/or the environment to power the sensors and the electronics. Such battery-free devices have the potential to revolutionize the medical industry by empowering individuals to gain control of their own health while significantly reducing medical costs by decreasing the need for frequent doctor visits.

The project introduces a flexible electronic energy harvesting device that can be worn on the body to harvest excess body heat and convert it to electrical energy. The device relies on a unique liquid-metal material which conducts electricity like a metal while offering water-like viscosity to realize electrical circuitry with ultimate flexibility and stretchability. The technology is compatible with roll-to-roll manufacturing, a highly desirable attribute in flexible electronics to reduce costs. The primary goal of the project is to increase the technology readiness of the harvester to increase its commercialization potential. The research includes systematic studies geared toward assessing and improving the long-term reliability of the harvester while enhancing its manufacturability by introducing materials and processes that offer lower-cost and manufacturing ease without compromising device performance. Research tasks include new flexible materials for enhanced performance, comfort, and robustness. The new materials and devices will be tested on the human body during different physical activity levels and under different ambient conditions. The harvesters will be subjected to repetitive cycles of external stresses such as heat, moisture and mechanical deformation. The results will be used to identify potential failure mechanisms, materials and process solutions will address such mechanisms.

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.