A highly sensitive strain sensor with a sandwich structure composed of two silver nanoparticles layers and one silver nanowires layer for human motion detection

Applications of flexible electronics related to cardiocerebral vascular system

Ensuring accessible and high-quality healthcare worldwide requires field-deployable and affordable clinical diagnostic tools with high performance. In recent years, flexible electronics with wearable and implantable capabilities have garnered significant attention from researchers, which functioned as vital clinical diagnostic-assisted tools by real-time signal transmission from interested targets in vivo. As the most crucial and complex system of human body, cardiocerebral vascular system together with heart-brain network attracts researchers inputting profuse and indefatigable efforts on proper flexible electronics design and materials selection, trying to overcome the impassable gulf between vivid organisms and rigid inorganic units. This article reviews recent breakthroughs in flexible electronics specifically applied to cardiocerebral vascular system and heart-brain network. Relevant sensor types and working principles, electronics materials selection and treatment methods are expounded. Applications of flexible electronics related to these interested organs and systems are specially highlighted. Through precedent great working studies, we conclude their merits and point out some limitations in this emerging field, thus will help to pave the way for revolutionary flexible electronics and diagnosis assisted tools development.

Advances in constructing silver nanowire-based conductive pathways for flexible and stretchable electronics

With their soaring technological demand, flexible and stretchable electronics have attracted many researchers' attention for a variety of applications. The challenge which was identified a decade ago and still remains, however, is that the conventional electrodes based on indium tin oxide (ITO) are not suitable for ultra-flexible electronic devices. The main reason is that ITO is brittle and expensive, limiting device performance and application. Thus, it is crucial to develop new materials and processes to construct flexible and stretchable electrodes with superior quality for next-generation soft devices. Herein, various types of conductive nanomaterials as candidates for flexible and stretchable electrodes are briefly reviewed. Among them, silver nanowire (AgNW) is selected as the focus of this review, on account of its excellent conductivity, superior flexibility, high technological maturity, and significant presence in the research community. To fabricate a reliable AgNW-based conductive network for electrodes, different processing technologies are introduced, and the corresponding characteristics are compared and discussed. Furthermore, this review summarizes strategies and the latest progress in enhancing the conductive pathway. Finally, we showcase some exemplary applications and provide some perspectives about the remaining technical challenges for future research.

Silver Nanowires in Stretchable Resistive Strain Sensors

Silver nanowires (AgNWs), having excellent electrical conductivity, transparency, and flexibility in polymer composites, are reliable options for developing various sensors. As transparent conductive electrodes (TCEs), AgNWs are applied in optoelectronics, organic electronics, energy devices, and flexible electronics. In recent times, research groups across the globe have been concentrating on developing flexible and stretchable strain sensors with a specific focus on material combinations, fabrication methods, and performance characteristics. Such sensors are gaining attention in human motion monitoring, wearable electronics, advanced healthcare, human-machine interfaces, soft robotics, etc. AgNWs, as a conducting network, enhance the sensing characteristics of stretchable strain-sensing polymer composites. This review article presents the recent developments in resistive stretchable strain sensors with AgNWs as a single or additional filler material in substrates such as polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), polyurethane (PU), and other substrates. The focus is on the material combinations, fabrication methods, working principles, specific applications, and performance metrics such as sensitivity, stretchability, durability, transparency, hysteresis, linearity, and additional features, including self-healing multifunctional capabilities.