Flexible electrochromic devices (FECDs) are widely explored for diverse applications including wearable electronics, camouflage, and smart windows. However, the manufacturing process of patterned FECDs remains complex, costly, and non‐customizable. To address this challenge, a strategy is proposed to prepare integrated FECDs via multi‐material direct writing 3D printing. By designing novel viologen/polyvinyl alcohol (PVA) hydrogel inks and systematically evaluating the printability of various inks, seamless interface integration can be achieved, enabling streamlined manufacturing of patterned FECDs with continuous production capabilities. The resultant 3D‐printed FECDs exhibit excellent electrochromic and mechanical properties, including high optical contrast (up to 54% at 360 nm), nice cycling stability (less than 5% electroactivity reduction after 10 000 s), and mechanical stability (less than 19% optimal contrast decrease after 5000 cycles of bending). The potential applications of these 3D‐printed hydrogel‐based FECDs are further demonstrated in wearable electronics, camouflage, and smart windows.

Flexible transparent electrodes (FTEs) are essential sections for wearable and other flexible optoelectronic devices. The application of traditional indium tin oxide (ITO) electrodes in flexible devices is limited by its poor mechanical stability and expensive manufacturing equipment costs. In this work, composite FTEs are achieved by combining one-dimensional silver nanowires (AgNWs) with two-dimensional transition-metal carbide (Ti₃C₂T_x MXene). The one and two-dimensional (1D:2D) structured composite AgNW:MXene FTE is generated under electrostatic interaction. 2D MXene nanosheets fill the voids of the AgNW networks and weld the wire–wire junctions by the effect of capillary force. The AgNW:MXene FTEs obtain superb photoelectric performance with a low sheet resistance of 10.91 Ω sq⁻¹ and high transmittance of 82.84%. Besides, the AgNW:MXene FTEs show high mechanical robustness after 1000 bending tests at a curvature radius of 5 mm and long-term stability (60% relative humidity and 120 °C). Eventually, the AgNW:MXene FTEs are integrated into 0.1 cm² perovskite solar cells (PSCs) and organic photovoltaics (OPVs), exhibiting a high power conversion efficiency (PCE) of 20.22% and 16.03%, respectively. The stability and mechanical properties of the corresponding flexible devices are also improved.

Supercapacitors are widely used in various fields due to their high power density, fast charging and discharging speeds, and long service life. However, with the increasing demand for flexible electronics, integrated supercapacitors in devices are also facing more challenges, such as extensibility, bending stability, and operability. Despite many reports on stretchable supercapacitors, challenges still exist in their preparation process, which involves multiple steps. Therefore, we prepared stretchable conducting polymer electrodes by depositing thiophene and 3-methylthiophene on patterned 304 stainless steel (SS 304) through electropolymerization. The cycling stability of the prepared stretchable electrodes could be further improved by protecting them with poly(vinyl alcohol)/sulfuric acid (PVA/H₂SO₄) gel electrolyte. Specifically, the mechanical stability of the polythiophene (PTh) electrode was improved by 2.5%, and the stability of the poly(3-methylthiophene (P3MeT) electrode was improved by 7.0%. As a result, the assembled flexible supercapacitors maintained 93% of their stability even after 10,000 cycles of strain at 100%, which indicates potential applications in flexible electronics.

Hydrogels are emerging as promising candidates for solar-driven interfacial evaporation in water purification. Our research introduces a graphite polyvinyl alcohol hydrogel (GPVA) evaporator designed as a photothermal conversion interface, showcasing high performance with an evaporation rate of 2.43 kg m−2 h−1 and an efficiency of 91.9% under solar irradiance of 1 kW m−2. The layered graphite structure of the GPVA hydrogel enhances its ion and dye adsorption capabilities, effectively removing fluoride, iodine, and other contaminants from water. In cyclic evaporation tests, the GPVA hydrogel evaporator demonstrated remarkable stability and long-term durability, maintaining an evaporation rate of 2.43 ± 0.11 kg m−2 h−1. The straightforward preparation of the GPVA hydrogel positions it as a compelling candidate for treating seawater and wastewater containing specific ions, presenting significant potential for water purification applications.

Strain sensors are essential for accurately capturing intricate motions across various applications. However, achieving both high mechanical strength and stability in strain sensors remains challenging. Herein, we present a novel and high-performance strain sensor using an amino-ended hyperbranched polyamide (HBPN) as a cross-linker to construct a strong and tough conducting polymer hydrogel composed of polyvinyl alcohol (PVA) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). The terminal amino groups in HBPN create non-covalent cross-links within the network, resulting in a robust structure. Notably, the unique hyperbranched topology of HBPN significantly enhances the hydrogel's properties, providing superior strength and toughness compared to its non-hyperbranched counterparts. Specifically, the distinctive macromolecular structure and abundant hydrogen bonding in the HBPN–PVA–PEDOT:PSS conducting polymer hydrogel result in exceptional toughness (991.53 kJ m⁻³), which is five times higher than that of the PVA–PEDOT:PSS hydrogel without HBPN. Additionally, the HBPN cross-linker enhances the sensitivity of the conducting polymer hydrogel, making it more responsive than linear analogs when used as a strain sensor. The resulting sensors adapt dynamically to human motion, demonstrating excellent detection capabilities. This work showcases a promising approach for developing cost-effective, sustainable, flexible, and high-performance wearable devices.