Transparent Electronics for Wearable Electronics Application

Abstract

Recent advancements in wearable electronics offer seamless integration with the human body for extracting various biophysical and biochemical information for real-time health monitoring, clinical diagnostics, and augmented reality. Enormous efforts have been dedicated to imparting stretchability/flexibility and softness to electronic devices through materials science and structural modifications that enable stable and comfortable integration of these devices with the curvilinear and soft human body. However, the optical properties of these devices are still in the early stages of consideration. By incorporating transparency, visual information from interfacing biological systems can be preserved and utilized for comprehensive clinical diagnosis with image analysis techniques. Additionally, transparency provides optical imperceptibility, alleviating reluctance to wear the device on exposed skin. This review discusses the recent advancement of transparent wearable electronics in a comprehensive way that includes materials, processing, devices, and applications. Materials for transparent wearable electronics are discussed regarding their characteristics, synthesis, and engineering strategies for property enhancements. We also examine bridging techniques for stable integration with the soft human body. Building blocks for wearable electronic systems, including sensors, energy devices, actuators, and displays, are discussed with their mechanisms and performances. Lastly, we summarize the potential applications and conclude with the remaining challenges and prospects.

Materials-Driven Soft Wearable Bioelectronics for Connected Healthcare

“…AgNWs could easily form effective percolation networks with a low amount of materials consumption. The large interspacing between AgNWs renders the thin films with high optical transparency, making them an ideal candidate for stretchable transparent conductive electronics as imperceptible E-skins. , By the combination of kirigami engineering, the patterned transparent and stretchable AgNW electrode achieved over 400% stretchability and 80% transparency retention even after 10,000 cycles of stretching . Given their linear, large, and nonhysteric temperature coefficient of resistance, AgNW-based flexible thermoelectric and thermochromic devices also showed great potential as the negative feedback control system to maintain the target temperature under external environmental fluctuation and heat flux …”

“…Compared to bulk materials, wearable pressure sensors utilizing nanomaterials could achieve a conformal attachment to biological surfaces, enabling precise monitoring with rapid response times and high specificity for capturing various types of biophysical signals. Moreover, a variety of LDNs have been applied to the construction of wearable pressure sensors featuring unique functionalities such as high sensitivity, full transparency, ultrahigh stretchability, as well as self-healability …”

Recent Development of Implantable Chemical Sensors Utilizing Flexible and Biodegradable Materials for Biomedical Applications

“…Materials that are biodegradable or derived from natural sources, combined with conductive polymers (CPs) and carbon-based conductive materials have been employed to build eco-friendly sensors. Furthermore, the integration of transparent electrodes into electronic systems can maintain visual information when interfacing with complex physiological environments, enabling concurrent imaging analysis . Research on innovative biomaterials, manufacturing technologies, and layout specification yield implantable chemical sensors with potential capabilities in disease prevention, diagnosis, and treatment, which would otherwise be unattainable when employing traditional nondegradable and rigid sensors.…”

Lightweight, Self-Poled, Flexible Piezoelectric Tungsten Disulfide Quantum Dots-Reinforced PVDF-HFP-Based Nanogenerator

“…10 Further, the fabrication process of the flexible nanogenerator device needs sophisticated equipment and complicated processes such as lithography and e-beam process. 11,12 Moreover, in the fabrication of the flexible nanogenerator in a polymer matrix with various inorganic nanostructures, the morphology variation of the piezoelectric nanomaterials plays a significant role and usually, random distribution of the nanorods, nanosheets, nanorings, and nanobelts in polymers degrades the performance of the nanogenerators. 13,14 Therefore, to enhance the efficiency of flexible piezoelectric nanogenerators, the selection of piezoelectric nanomaterials' morphology with high piezoelectric properties is still a challenge and highly desirable.…”