Polyaniline (PANI), characterized by its proton-coupled redox mechanism and multicolor reversibility, is widely investigated for adaptive optical interfaces. Compared to inorganic oxides, PANI offers advantages in cost-effectiveness, mechanical flexibility, and molecular tunability; however, its practical implementation faces challenges related to kinetic limitations and environmental instability. This review presents a comprehensive analysis of PANI-based electrochromic materials, examining the intrinsic correlations among synthesis methodologies, microstructural characteristics, and optoelectronic performance. Synthesis strategies, including chemical oxidative polymerization, electrochemical deposition, and template-assisted techniques, are evaluated. Emphasis is placed on resolving the trade-off between optical contrast and switching kinetics by constructing high-surface-area porous nanostructures and inducing chain ordering via functional dopants to shorten ion diffusion paths and reduce charge transfer resistance. Fundamental electrochromic properties are subsequently discussed, with specific attention to degradation mechanisms triggered by environmental factors, such as pH drift, and stabilization strategies involving electrolyte engineering and composite design. Furthermore, the review addresses the evolution of applications from single-band monochromatic displays to dual-band smart windows for decoupled visible/near-infrared regulation and multifunctional integrated systems, including electrochromic supercapacitors and adaptive thermal management textiles. Finally, technical challenges regarding long-term durability, neutral color development, and large-area manufacturing are summarized to outline future research directions for PANI-based optical systems.

Fully stretchable hydrogel-based moisture-electric generators (FSHMEGs) are promising power sources for wearable and implantable electronics. Current FSHMEGs are constrained by low electrical output and mechanical fragility, mainly due to weak interfacial adhesiveness within multilayered architectures. Here, we introduce an intrinsically adhesive hydrogel that forms robust hydrogel-electrode interfaces, enabling efficient transfer of both electrical charges and mechanical loads during deformation. As a result, the device delivers an open-circuit voltage of 0.94 V and a current density of 141 µA cm ⁻² at 85% relative humidity, and maintains stable output for more than 220 h. The reinforced interface also imparts exceptional mechanical durability, exhibiting only negligible performance degradation after 8000 folding cycles and 1000 stretching cycles at 80% strain. Benefiting from rapid humidity responsiveness and continuous power delivery, the device enables non-invasive respiration monitoring and can directly power wearable electronics (e.g., electrocardiogram (ECG) sensors). This interfacial-engineering strategy offers a practical pathway toward high-performance moisture-electric generators with broad potential in energy harvesting, bioelectronics, and self-powered sensing systems.

Silver nanowire (AgNW) networks have attracted significant attention as leading candidates for flexible transparent electrodes owing to their unique combination of high electrical conductivity, optical transparency, and mechanical compliance. This review presents an overview of recent developments in AgNW-based transparent electrode technologies, with particular emphasis on strategies to improve network conductivity and long-term reliability, including junction engineering, surface modification, encapsulation approaches, and composite structure design. Representative applications in flexible optoelectronic systems, such as organic light-emitting devices, transparent heating elements, and electrochromic platforms, are also discussed. Finally, current challenges and future research directions toward scalable manufacturing and practical implementation of high-performance AgNW electrodes are outlined.