Development of more sustainable materials for textile-based triboelectric nanogenerators (T-TENGs) is crucial for the on-going transition in manufacturing of next-generation wearable technologies. Sustainability and recyclability of such new materials are important. This facilitates the introduction of cellulose-based materials as an active TENG material. In this work, cellulose acetate, generally recognized as a biodegradable polymer, is used to prepare triboelectric electrospun mats. The electrospinning technique is applied to optimize the cellulose acetate mat morphology, structure, and mechanical properties. The TENG performance and overall mechanical properties are further optimized by combining the electrospun cellulose acetate mats with nylon-6 (i.e., polyamide 6) mats to form the T-TENGs via integration with conductive cotton textile. The mechanical stability and electrical performance of the cellulose acetate and nylon electrospun mats is verified in 50 000 cycles. The formed T-TENG also demonstrated a good triboelectric performance with a maximum peak-to-peak voltage >400 V, maximum current >11 µA, and peak power of ≈3 mW.

This article presents a novel, high-performance, screen-printable zinc (Zn)-based ink and a chemical sintering process that significantly improves long-term air stability. The ink formulation combines micro- and nanoparticles, enhancing electrical conductivity—up to 10 times compared to microparticle-only inks. Micro-fibrillated cellulose (Exilva) is used as a sustainable binder, aligning with eco-friendly electronics initiatives. Besides the formulation, the benefit of a multistep chemical sintering approach, based on the sequential immersion of the printed structures in acetic acid solution, is demonstrated. If with a more conventional one-step acetic acid sintering treatment a conductivity of ≈3.18 × 10⁵ S m−¹ can be achieved, the use of the multi-step process further enhances both conductivity, increasing conductivity ≈2.6 times to ≈8.37 × 10⁵ S m−¹ (sheet resistance 0.06 Ω □−¹), it is the highest reported value achieved through chemical sintering—just 20 times lower than bulk Zn (≈16.6 × 10⁶ S m−¹). Importantly, the ink, following the proposed chemical sintering and without encapsulation also exhibits outstanding air stability, maintaining functionality with only an ≈11% increase in resistance after 6 months in ambient conditions (40–60% RH). By offering superior durability, flexibility, and, most notably, unprecedented air stability, this Zn-based ink presents a significant advancement for sustainable and flexible electronics.

Combining UV radiation with vapor phase polymerization (VPP) enables the fabrication of conducting polymer films with tunable electrical, optical, and electrochemical properties. However, traditional mask-based UV exposure typically requires separation between a photomask and the sample, which limits resolution. This study circumvents this by using a maskless UV exposure system that directly projects high-resolution patterns onto the substrate. Using poly(3,4-ethylenedioxythiophene):toluenesulfonate (PEDOT:Tos) as a model material, the resulting minimum feature sizes are approximately 8 µm—nearly half of what has been achieved using mask-based systems. We find that the obtained resolution is not limited by the optics but is related to material aspects such as molecular diffusion, providing guidelines for further optimizations. Our findings also show that the total delivered dose, rather than exposure time or irradiance, controls the film properties. The resulting PEDOT:Tos patterns exhibit distinct, stable color variations during electrochemical switching, highlighting the potential of maskless UV-VPP for high-resolution electrochromic displays.

Iron-catalyzed laser-induced graphitization (IC-LIG) represents an eco-efficient alternative to traditional carbon electrode manufacturing. Combining a bio-based tannic acid–iron precursor ink with CO<inf>2</inf> laser treatment results in sheet resistance of 23.59 ± 1.2Ω □−1 on renewable substrates. Varying the tannic-acid-to-iron ratio (TA:Fe), the rheology of the precursor ink can be tuned, enabling versatile application techniques, including spray coating, screen printing, and direct-ink-writing (DIW). Subsequent laser-treatment enables the formation of functional IC-LIG electrodes for all application methods, while even thick DIW-printed layers (260 µm) result in complex, conductive electrode patterns. Laser post-treatment expands design possibilities by locally tuning iron phases, such as converting γ-iron to magnetite. The unidirectional laser-treatment results in a layered arrangement, forming a multilayer electrode with a highly graphitized top layer serving as a current collector substitute, and an underlying composite of iron-rich nanoparticles embedded in a porous graphitic foam, acting as a hybrid electrode. Electrochemical analysis reveals double-layer capacitor behavior at low TA:Fe ratios, while higher ratios demonstrate increased redox activity and pseudo-capacitive characteristics. Achieving stable capacities of 15 mF cm−2 with a 1 M NaCl electrolyte over 5000 cycles underscores the potential of IC-LIG electrodes as a sustainable solution for advanced energy storage devices and beyond.

Membranes and separators are crucial components in many processes and devices. The state-of-the-art fossil-based membranes have a high carbon footprint, and polyfluorinated membranes are increasingly phased out. These limitations lead to an inevitable transition that calls for carbon-neutral membranes with the same or even better performance that can be produced at scale and low cost. Cellulose membranes have the potential to fulfill these criteria if they can be tuned for different purposes. A way to tailor cellulose membranes by preparing them from cellulose fibrils of different refining degrees is presented. The membranes’ effective pore size and permeability to PEG, Fluorescein, and different ions were characterized. The membranes were efficiently used as separators in aqueous-based Zn-ion batteries and PEDOT supercapacitors. This work demonstrates a route toward high-performing and versatile cellulose membranes that can be produced at scale in a more sustainable membrane industry. 

Compliant vibrating soft actuators made with dielectric elastomer actuators are successfully assembled with mechanical energy harvesters, which operate a few hundred volts. The TENG-DEA module as a sensor-actuator fusion is applicable to wearable haptic systems, which are self-powering as well as sensing mechanical touches. The modules provide a solution for compliant and lightweight energy-generating, sensing and actuation functions to wearable haptic systems.

With the increasing global demand for net-zero carbon emissions, actions to address climate change have gained momentum among policymakers and the public. The urgent need for a sustainable economy is underscored by the mounting waste crisis in landfills and oceans. However, the proliferation of distributed electronic devices poses a significant challenge due to the resulting electronic waste. To combat this issue, the development of sustainable and environmentally friendly materials for these devices is imperative. Cellulose, an abundant and CO2-neutral substance with a long history of diverse applications, holds great potential. By integrating electrically interactive components with cellulosic materials, innovative biobased composites have been created, enabling the fabrication of bulk electroactive paper and the establishment of new, potentially more sustainable manufacturing processes for electronic devices. This review explores recent advances in bulk electroactive paper, including the fundamental interactions between its constituents, manufacturing techniques, and large-scale applications in the field of electronics. Furthermore, it addresses the importance and challenges of scaling up production of electroactive paper, highlighting the need for further research and development.

Materials that provide dynamically tunable infrared (IR) response are important for many applications, including active camouflage and thermal management. However, current IR-tunable systems often exhibit limitations in mechanical properties or practicality of their tuning modalities, or require complex and costly fabrication methods. An additional challenge relates to providing compatibility between different spectral channels, such as allowing an object to be reversibly concealed in the IR without making it appear in the visible range. Here, we demonstrate that conducting polymer-cellulose papers, fabricated through a simple and cheap approach, can overcome such challenges. The papers exhibit IR properties that can be electrochemically tuned with large modulation (absolute emissivity modulation of 0.4) while maintaining largely constant response in the visible range. Owing to high ionic and electrical conductivity, the tuning of the top surface can be performed electrochemically from the other side of the paper even at tens of micrometer thicknesses, removing the need for overlaying electrode and electrolyte in the optical beam path. These features enabled a series of electrically tunable IR devices, where we focus on demonstrating dynamic radiative coolers, thermal camouflage, anti-counterfeiting tags, and grayscale IR displays. The conducting polymer-cellulose papers are sustainable, cheap, flexible and mechanically robust, providing a versatile materials platform for active and adaptive IR optoelectronic devices. (Figure presented.). 

The transition to sustainable materials and eco-efficient processes in commercial electronics is a driving force in developing green electronics. Iron-catalyzed laser-induced graphitization (IC-LIG) has been demonstrated as a promising approach for rendering biomaterials electrically conductive. To optimize the IC-LIG process and fully exploit its potential for future green electronics, it is crucial to gain deeper insights into its catalyzation mechanism and structural evolution. However, this is challenging due to the rapid nature of the laser-induced graphitization process. Therefore, multiscale preparation techniques, including ultramicrotomy of the cross-sectional transition zone from precursor to fully graphitized IC-LIG electrode, are employed to virtually freeze the IC-LIG process in time. Complementary characterization is performed to generate a 3D model that integrates nanoscale findings within a mesoscopic framework. This enabled tracing the growth and migration behavior of catalytic iron nanoparticles and their role during the catalytic laser-graphitization process. A three-layered arrangement of the IC-LIG electrode is identified including a highly graphitized top layer with an interplanar spacing of 0.343 nm. The middle layer contained γ-iron nanoparticles encapsulated in graphitic shells. A comparison with catalyst-free laser graphitization approaches highlights the unique opportunities that IC-LIG offers and discuss potential applications in energy storage devices, catalysts, sensors, and beyond.

Nanocellulose-based membranes have attracted intense attention in bioelectronic devices due to their low cost, flexibility, biocompatibility, degradability, and sustainability. Herein, we demonstrate a flexible ionic diode using a cross-linked bipolar membrane fabricated from positively and negatively charged cellulose nanofibrils (CNFs). The rectified current originates from the asymmetric charge distribution, which can selectively determine the direction of ion transport inside the bipolar membrane. The mechanism of rectification was demonstrated by electrochemical impedance spectroscopy with voltage biases. The rectifying behavior of this kind of ionic diode was studied by using linear sweep voltammetry to obtain current-voltage characteristics and the time dependence of the current. In addition, the performance of cross-linked CNF diodes was investigated while changing parameters such as the thickness of the bipolar membranes, the scanning voltage range, and the scanning rate. A good long-term stability due to the high density cross-linking of the diode was shown in both current-voltage characteristics and the time dependence of current.