Professor of electrical and computer Engineering, NC State university
Title: Enabling Self-Powered Monitoring: Advances in Micro-Power Thermoelectric Generators for IoT Sensors and Wearables
The advent of self-powered wearable sensor nodes and electronic devices has engendered a plethora of possibilities for the seamless integration of health and wellness monitoring into the daily lives of individuals. Progress in the realms of energy efficiency and harvesting, along with the concurrent optimization of form factors and augmentation of functionalities, have been particularly salient. A self-powered wearable system typically comprises sensors, an energy harvesting device, a power management unit, energy storage capability, a data transmission component, and a data processing platform. We will delve into the recent research and prevalent challenges associated with the constituent parts of a self-powered wearable system, with a particular emphasis on energy harvesting. A succinct overview of fundamental concepts is supplemented by an analysis of several systems showcased for wearable applications. In parallel, we also examine the current research and industrial endeavours aimed at creating a network of self-powered wearable devices that can operate continuously over extended periods by harvesting heat from available sources. In particular, we will discuss the application of micro-power thermoelectric generators, an emerging field with many new and exciting applications including self-powered, wearable devices for the consumer market, continuous health and performance monitoring devices for personal use and clinical studies, as well as sensors and communications equipment installed on pipelines and a variety of industrial machines that require continuous, hassle-free monitoring.
Despite the strong drive for the development of self-powered wearable systems, the performance of micro-power thermoelectric generators (TEGs) manufactured so far may not always be sufficient to support the power needs of sensors and electronics that must operate continuously with high reliability. In certain instances, TEGs may be capable of meeting the power requirements of low-power sensors, while in others they may fall short. The reasons behind the inefficiency of these devices include their incompatibility with state-of-the-art thermoelectric materials, compromises made in device design mandated by the resolution and throughput of the deposition techniques, and large thermal parasitic resistances introduced by supporting materials used in their packaging. We present results highlighting some challenging trade-offs observed while fabricating rigid and flexible modular devices that can be integrated with a shirt and a smartwatch.
Daryoosh Vashaee is a Professor at North Carolina State University, where he holds dual appointments in the departments of Electrical and Computer Engineering and Materials Science and Engineering. He serves as the director of the Nanoscience and Quantum Engineering Research Laboratory (NQERL) and is a member of the ASSIST Engineering Research Center. In ASSIST, he led the research on thermoelectric materials, with a focus on developing self-powered wearable health and environmental monitoring systems. He is recognized as an expert in the fields of nanostructured thermoelectrics, and has made significant contributions to the development of these structures, including heterostructure thermionic devices and nanocomposite thermoelectric materials. Professor Vashaee was honored with the Goldsmid Award from the International Thermoelectric Society, which recognizes research excellence in the field of thermoelectrics, and NSF Career award. He received his Ph.D. from the University of California, Santa Cruz and has held postdoctoral positions at MIT and assistant professor at Oklahoma State University. He has been on the faculty at North Carolina State University since 2014.
Host: Dr. Mona Zebarjadi
Organizer: Dr. Mona Zebarjadi