Color imaging systems that underpin modern technologies still suffer in low-light conditions because of the inherently lossy filtering mechanism of conventional Bayer color filters. Although Bayer-type filters integrated with complementary metal–oxide–semiconductor sensors remain the dominant architecture, they typically transmit only about 30% of incident white light, leading to noisy images under weak illumination. Color routers offer an alternative by redirecting different spectral components of light to corresponding photodiodes in the near field. While recent color routers based on high-refractive-index metasurfaces have shown promise, low-refractive-index materials remain largely unexplored despite their potential for higher transmittance and cost-effective mass production. Here, we demonstrate inverse-designed, two-photon-polymerization 3D-printed pixel-level color routers using low-index IP-L resin (n ≈ 1.5). The color routers achieve transmittance of ~87% in simulation and ~70% experimentally across the visible spectrum. Monochrome-sensor imaging further confirms improved color fidelity and shorter exposure times, highlighting their potential for next-generation high-efficiency imaging platforms. The authors demonstrate a 3D-printed low-refractive-index color router that replaces absorptive color filters, improving light collection and enabling brighter, more efficient color imaging under both normal and low-light conditions.
Electroadhesion (EA) offers low power consumption, material versatility, and precise force control for soft robotics. This review examines EA principles, key performance variables, and recent advances in dielectric and electrode materials. Applications such as clutches, grippers, climbing robots, and haptic interfaces are discussed. Challenges remain, including high electric field requirement and slow response. Future directions include low-voltage systems, sensing integration, advanced fabrication, and ionic-based EA technologies.
Transparent conductive materials (TCMs) are essential for optoelectrical devices ranging from smart windows and defogging films to soft sensors, display technologies, and flexible electronics. Materials, such as indium tin oxide (ITO) and silver nanowires (AgNWs), are commonly used and offer high optical transmittance and electrical conductivity, but suffer from brittleness, oxidation susceptibility, and require high-cost materials, greatly limiting their use. Carbon nanotube (CNT) networks provide a promising alternative, featuring mechanical compliance, chemical robustness, and scalable processing. This study reports an aqueous ink formulation composed of ultra-long mix-walled carbon nanotubes (UL-CNTs), compatible with the flow coating process, yielding uniform transparent conductive films (TCFs) on polyethylene terephthalate (PET), glass, and polycarbonate (PC). The resulting films exhibit tunable transmittance (85%–88% for single layers; ~57% for three layers at 550 nm) and sheet resistance of 7.5 kΩ/□ to 1.5 kΩ/□ accordingly. These TCFs maintain stable sheet resistance for over 5000 bending cycles and show excellent mechanical durability with negligible effects on heating performance. Post-deposition treatments, including nitric acid vapor doping or flash photonic heating (FPH), further reduce sheet resistance by up to 80% (7.5 kΩ/□ to 1.2 kΩ/□). X-ray photoelectron spectroscopy (XPS) results in reduced surface oxygen content after FPH. The photonic-treated heaters attain ~100 °C within 20 s at 100 V. This scalable, water-based process provides a pathway toward low-cost, flexible, and stretchable devices in a variety of fields, including printed electronics, optoelectronics, and thermal actuators.
Piezoelectric effect plays an important role in a variety of applications, such as sensors, nanogenerators and piezotronics. The performance of piezoelectric device is normally enhanced with increasing dimension of the piezoelectric layer and decreasing piezoelectric layer thickness. To meet the demand for producing superior piezoelectric films (as thin as 1 nm) with precise thickness and composition control, powerful fabrication techniques are essential. Atomic layer deposition (ALD) shows exceptional potential in preparing a wide range of materials with precise thickness control (due to its self-limiting growth nature at the Angstrom level) and capability of deposition on high aspect ratio surface. Here, we provide the introduction to ALD and highlight its unique features among other fabrication techniques, with reference to the state of the art on ALD preparation of different piezoelectric materials, including novel transition metal dichalcogenides (TMDs) and traditional Metal Oxides (MOs). Different ALD-related materials preparation strategies for the improvement of piezoelectricity are also discussed, together with future perspectives on the development of ALD-prepared piezoelectric materials. We believe ALD can enable wider applications of piezoelectricity due to its unique advantages. (c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
As a promising renewable resource for sustainable energy production and numerous bioproducts, lignocellulosic biomass (LCB) is derived from a variety of plant sources. Despite their diminishing resources and alarming environmental consequences, chemical and synthetic polymers are mainly manufactured using fossil fuels. The current dependence on fossil resources and their corresponding environmental impacts can be alleviated by producing chemicals and polymers from renewable natural resources. LCB is a highly renewable and affordable natural resource. As a rich source of feedstock for the production of biofuels, LCB offers an environmental and energy solution. The organic biomass of renewable resources is used to make biofuels, which include waste lignocellulosic biomass. Bioconversion has been accomplished via physical, chemical, and biological methods, so there are a variety of methods thathave been used. Alternative fuels derived from LCB must be developed to maintain the existence of the human race. There are still concerns about the cost-effectiveness of the process and the limits of the technology used to produce biofuel.
