Flexible Technologies for Self-Powered Wearable Health and Environmental Sensing

Abstract

| This article provides the latest advances from the NSF Advanced Self-powered Systems of Integrated sensors and Technologies (ASSIST) center. The work in the center addresses the key challenges in wearable health and environmental systems by exploring technologies that enable ultra-long battery lifetime, user comfort and wearability, robust medically validated sensor data with value added from multimodal sensing, and access to open architecture data streams. The vison of the ASSIST center is to use nanotechnology to build miniature, selfpowered, wearable, and wireless sensing devices that can enable monitoring of personal health and personal environmental exposure and enable correlation of multimodal sensors. These devices can empower patients and doctors to transition from managing illness to managing wellness and create a paradigm shift in improving healthcare outcomes. This article presents the latest advances in high-efficiency nanostructured energy harvesters and storage capacitors, new sensing modalities that consume less power, low power computation, and communication strategies, and novel flexible materials that provide form, function, and comfort. These technologies span a spatial scale ranging from underlying materials at the nanoscale to body worn structures, and the challenge is to integrate them into a unified device designed to revolutionize wearable health applications.

Low-Power Wearable Systems for Continuous Monitoring of Environment and Health for Chronic Respiratory Disease

“…The COTS SoC from Texas Instruments to collect and transmit the data consumed an additional 11.5 mW for each form factor. As summarized in the next section, we are in the process of developing a custom ASSIST SoC to bring this power consumption down to 30 µW [8]. …”

“…The vision of the ASSIST Center is to utilize nano-enabled low-power sensors, low-power computational and communication circuits, and energy harvesting devices from body heat and motion [8]. These technologies are used for designing wearable and wireless systems for data collection for multi-modal and simultaneous sensing of human physiology, behavior, and environment for correlation and subsequent wellness management.…”

“…Under the National Science Foundation Nanosystems Engineering Research Center for Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST), we develop key core technologies for achieving a high-performance, multi-functional, self-powered environmental and biomedical sensing system that targets maximizing the power harvested from the body in the form of heat and movement while simultaneously minimizing the power consumed via low-power sensing, subthreshold CMOS computation, novel transistor designs, and ultra-low power radios [8], [9]. In this paper, we investigate the feasibility of engineering a system for long-term, continuous monitoring of wellness status and of relevant environmental factors around those with respiratory problems, such as asthma, during their daily-life activities.…”

“…Within the ASSIST Center, we have defined 500µW/cm 2 as an appropriate target for our energy harvesters and plan on being able to support 1mW of power consumption [8]. While separate research is underway to develop an ultra-low power radio, system on chip (SoC) and thermoelectric devices to harvest thermal radiation from the body [8], [9], in this article we report our efforts towards reducing the power levels of sensors and sensor front-end electronics to sub-milliwatt levels with our primary contributions being the development of an ultra-low power ozone sensor, VOC sensor, spirometer, and the integration of these and other sensors into a low power health and environmental sensing platform. The paper outline is as follows: In Section II, we describe the general architecture of such a wearable system for simultaneous health and environment monitoring in the context of asthma management.…”

Development of a fiber-based membraneless hydrogen peroxide fuel cell

“…1 One of the main issues associated with the design of exible devices is the mechanical strength of the components including the substrate, which are subjected to varying types of stress such as bending and stretching. An effective approach to mitigate the mechanical strength issue is to lower the substrate thickness, decreasing the stress during different loading steps.…”