| dc.description.abstract | In the burgeoning field of flexible hybrid electronics (FHE), which have attracted significant attention for their potential applications such as IoT sensors, flexible power sources, biomedical applications in sector of healthcare, fitness, and environmental monitoring, the challenge of ensuring reliability under extreme environments is compounded by the inherently nonlinear behaviors these devices exhibit, such as large deformation, transient motions, non-harmonic oscillations, etc. Consequently, their reliability and sustainability under various mechanical and environmental conditions remain a critical concern. The complexity of these reliability issues is further amplified by their multidisciplinary nature, straddling the boundaries of multi-scale and multi-physics domains. Users of wearable electronics, for instance, may be concerned about the potential for device failure or degradation due to factors like accidental drops, misuse, overheating, or the natural wear and tear over the product's lifecycle. While manufacturers provide specifications and guidelines to address these concerns, significant uncertainties remain, potentially leading to consumer mistrust or even physical harm. This dissertation presents a comprehensive study on development of advanced manufacturing technology focusing on additive printing to address the sustainability issues due to the effects of mechanical and environmental factors on the performance and reliability of FHE. This is to transform the discipline of reliability engineering by creating systems capable of not only enduring extreme environmental conditions but also intelligently adapting to them. This is supported by a cross-disciplinary strategy that merges insights from mechatronics and electronic design, aiming to expand the possibilities in various fields. This research primarily focuses on the realms of Wearable Electronics, Biosensors, Renewable Energy Storage, alongside advanced manufacturing focusing additive printing.
Chapter 1 provides an introduction to the field of flexible hybrid electronics, wearable biosensors, and their potential applications. The challenges associated with their durability and reliability under mechanical and environmental stresses are discussed. This chapter also outlines the objectives, scope, and methodology of the dissertation, emphasizing the improvement of fabrication methods, the development of calibration methods, and the assessment of reliability.
Chapter 2 expand the introductory topics to preliminaries and methodologies in this study. This topic includes the additive manufacturing of in-mold electronics (IME) focused on fabricating biosensor by using print techniques, followed by reliability testing that mimic real-life motions. Additionally, standardized reliability testing methods and failure criteria, particularly for wearable devices subject to the stresses of human motion will be discussed.
Chapter 3 explores the advances of this study on additively printed sensors, including the system level manufacturing of wearable IoT sensors, energy-efficient embedded system, improvement of sensing accuracy, hygrothermal reliability, real-time signal processing, real-time calibration methods with integration of various sensors using machine learning and wireless connectivity. The chapter also explores the functional tests, characterization, and reliability testing of the fabricated sensors.
Chapter 4 focuses on flexible batteries, discussing the advances of this study on flexible battery assessment, experimental analysis of flexible reliability, and the development of state of health (SOH) prediction models in various aging conditions. The chapter also covers the development of a fully automated diagnostic system for battery SOH, flexible reliability tests on SOH degradation, and the exploration of various SOH prediction models.
Prediction models and simulations will be portrayed at the end of each chapter 3 and 4 about the behavior of sensors, covering finite element method (FEM) modeling of FPCB and life prediction models, multiphysics simulation of water diffusion and capacitance variation of humidity sensors and analysis of biosignal from EDA sensors.
Chapter 5 summarizes the reliability of additively printed sensor patches and the flexible power sources, discussing the contributions, limitations, and future directions of the research. It will conclude the dissertation by highlighting the achievements and significance of the research, as well as the practical applications of the developed flexible hybrid electronics and wearable biosensors.
This dissertation is expected to advance the understanding of the effects of mechanical and environmental factors on the durability and reliability of flexible hybrid electronics (FHE) and wearable biosensors. It might provide a comprehensive study of additively printed sensors and flexible power sources, focusing on their performance, reliability, and potential applications. The research conducted in this study might be essential for the future development and integration of FHE and wearable biosensors in various industries, including healthcare, aerospace, and automotive.
The work presented in this dissertation might contribute to the development of sustainable additive manufacturing of electronic devices for sensing and power sourcing applications. By investigating the fabrication methods, calibration techniques, and reliability testing of additively printed sensors and flexible batteries, the study might offer valuable insights into the challenges and opportunities associated with these emerging technologies. The development of accurate and reliable sensors is assumed critical for real-time monitoring of physiological signals, such as temperature, humidity, electrodermal activity, and pulse oximetry, which have significant implications for patient care and well-being.
Moreover, the research expects to understand the failure mechanism and the prediction of life for wearable electronics. Understanding the behavior of these devices under various mechanical and environmental conditions might be crucial for ensuring their long-term reliability and functionality. The dissertation also explores the development and optimization of state-of-health (SOH) prediction models for flexible batteries, which might be essential for the efficient and reliable operation of wearable devices.
Furthermore, the practical applications of this research might extend beyond healthcare to other industries where flexible and conformable electronics are increasingly being adopted. The findings of this dissertation have the potential to drive innovation in the design, fabrication, and integration of FHE and wearable biosensors, ultimately leading to more robust, reliable, and efficient electronic devices.
In conclusion, this dissertation is expected to provide a thorough investigation into the effects of mechanical and environmental factors on the durability and reliability of FHE and wearable biosensors. The comprehensive study present herein not only addresses the current research gaps and challenges but also might highlight the potential applications and future directions of these rapidly evolving technologies. As wearable electronics continue to gain traction in various industries, the insights and contributions of this research might play a vital role in shaping the future of flexible hybrid electronics and wearable biosensors. | en_US |
