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This paper presents innovations in green electronic and computing technologies. The importance and the status of the main subjects in green electronic and computing technologies are presented in this paper. In the last semicentennial, the planet suffered from rapid changes in climate. The planet is suffering from increasingly wild storms, hurricanes, typhoons, hard droughts, increases in seawater height, floods, seawater acidification, decreases in groundwater reserves, and increases in global temperatures. These climate changes may be irreversible if companies, organizations, governments, and individuals do not act daily and rapidly to save the planet. Unfortunately, the continuous growth in the number of computing devices, cellular devices, smartphones, and other smart devices over the last fifty years has resulted in a rapid increase in climate change. It is severely crucial to design energy-efficient "green" technologies and devices. Toxic waste from computing and cellular devices is rapidly filling up landfills and increasing air and water pollution. This electronic waste contains hazardous and toxic materials that pollute the environment and affect our health. Green computing and electronic engineering are employed to address this climate disaster. The development of green materials, green energy, waste, and recycling are the major objectives in innovation and research in green computing and electronics technologies. Energy-harvesting technologies can be used to produce and store green energy. Wearable active sensors and metamaterial antennas with circular split ring resonators (CSSRs) containing energy-harvesting units are presented in this paper. The measured bandwidth of the matched sensor is around 65% for VSWR, which is better than 3:1. The sensor gain is 14.1 dB at 2.62 GHz. A wideband 0.4 GHz to 6.4 GHz slot antenna with an RF energy-harvesting unit is presented in this paper. The Skyworks Schottky diode, SMS-7630, was used as the rectifier diode in the harvesting unit. If we transmit 20 dBm of RF power from a transmitting antenna that is located 0.2 m from the harvesting slot antenna at 2.4 GHz, the output voltage at the output port of the harvesting unit will be around 1 V. The power conversion efficiency of the metamaterial antenna dipole with metallic strips is around 75%. Wearable sensors with energy-harvesting units provide efficient, low-cost healthcare services that contribute to a green environment and minimize energy consumption. The measurement process and setups of wearable sensors are presented in this paper. [ABSTRACT FROM AUTHOR]

Extensive research into green technologies is driven by the worldwide push for eco‐friendly materials and energy solutions. The focus is on synergies that prioritize sustainability and environmental benefits. This study explores the potential of abundant, non‐toxic, and sustainable resources such as paper, lignin‐enriched paper, and cork for producing laser‐induced graphene (LIG) supercapacitor electrodes with improved capacitance. A single‐step methodology using a CO2 laser system is developed for fabricating these electrodes under ambient conditions, providing an environmentally friendly alternative to conventional carbon sources. The resulting green micro‐supercapacitors (MSCs) achieve impressive areal capacitance (≈7–10 mF cm−2) and power and energy densities (≈4 μW cm‐2 and ≈0.77 µWh cm−2 at 0.01 mA cm−2). Stability tests conducted over 5000 charge–discharge cycles demonstrate a capacitance retention of ≈80–85%, highlighting the device durability. These LIG‐based devices offer versatility, allowing voltage output adjustment through stacked and sandwich MSCs configurations (parallel or series), suitable for various large‐scale applications. This study demonstrates that it is possible to create high‐quality energy storage devices based on biodegradable materials. This development can lead to progress in renewable energy and off‐grid technology, as well as a reduction in electronic waste. [ABSTRACT FROM AUTHOR]

Among the solid‐state lighting technologies, OLEDs occupy a prominent position for the high efficiencies associated with the low CO2 emissions. In line with the recent studies aimed at designing sustainable and biodegradable devices, herein we report on the synthesis of a series of iridium(III) complexes featuring, as β‐diketone ligands, curcumin and 6‐dehydrogingerdione, two natural compounds found in the rhizome of Curcuma longa and Zingiber officinale. To improve the solubility of both the ligands and prevent the aggregation of the complexes, oleoyl residues were inserted on the phenolic −OH groups. The resulting complexes exhibited a green emission with quantum yields as high as 2.8 % (relative to fluorescein). OLED devices were fabricated by using, as emitting layer, a host‐guest blend of the iridium complex in 4,4'‐bis(N‐carbazolyl)‐1,1'‐biphenyl (CBP). The morphological analysis revealed that thin films of the emitting layer were homogeneous. The devices fabricated with iridium complexes from 6‐dehydrogingerdione exhibited higher luminance, efficiency and power efficiency with respect to the corresponding devices obtained from curcumin; also the functionalization of the β‐diketone unit with the oleoyl residue proved to increase significantly the performance of the device. Overall, these data suggest that aggregation is a key factor that compromise the performances of the corresponding OLEDs. [ABSTRACT FROM AUTHOR]

The underutilization of digestate-derived polymers presents a pressing environmental concern as these valuable materials, derived from anaerobic digestion processes, remain largely unused, contributing to pollution and environmental degradation when left unutilized. This study explores the recovery and utilization of biodegradable polymers from biomass anaerobic digestate to enhance the performance of solar photovoltaic (PV) cells while promoting environmental sustainability. The anaerobic digestion process generates organic residues rich in biodegradable materials, often considered waste. However, this research investigates the potential of repurposing these materials by recovering and transforming them into high-quality coatings or encapsulants for PV cells. The recovered biodegradable polymers not only improve the efficiency and lifespan of PV cells but also align with sustainability objectives by reducing the carbon footprint associated with PV cell production and mitigating environmental harm. The study involves a comprehensive experimental design, varying coating thickness, direct normal irradiance (DNI) (A), dry bulb temperature (DBT) (B), and relative humidity (C) levels to analyze how different types of recovered biodegradable polymers interact with diverse environmental conditions. Optimization showed that better result was achieved at A = 8 W/m2, B = 40 °C and C = 70% for both the coated material studied. Comparative study showed that for enhanced cell efficiency and cost effectiveness, EcoPolyBlend coated material is more suited however for improving durability and reducing environmental impact NanoBioCelluSynth coated material is preferable choice. Results show that these materials offer promising improvements in PV cell performance and significantly lower environmental impact, providing a sustainable solution for renewable energy production. This research contributes to advancing both the utilization of biomass waste and the development of eco-friendly PV cell technologies, with implications for a more sustainable and greener energy future. This study underscores the pivotal role of exploring anaerobic digestate-derived polymers in advancing the sustainability and performance of solar photovoltaic cells, addressing critical environmental and energy challenges of our time.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 7 Given name: [Ashok] Last name [Kumar Yadav]. Also, kindly confirm the details in the metadata are correct.correct [ABSTRACT FROM AUTHOR]

Investigating biodegradable and biocompatible materials for electronic applications can lead to tangible outcomes such as developing green-electronic devices and reducing the amount of e-waste. The proposed emulsion-based conducting ink formulation takes into consideration circular economy and green principles throughout the entire process, from the selection of materials to the production process. The ink is formulated using the biopolymer polylactic acid dissolved in a sustainable solvent mixed with water, along with conductive carbon nanotubes (CNTs) and silver flakes as fillers. Hybrid conductive fillers can lower the percolation threshold of the ink and the production costs, while maintaining excellent electrical properties. The coating formed after the deposition of the ink, undergoes isothermal treatment at different temperatures and durations to improve its adhesion and electrical properties. The coating's performance was evaluated by creating an eight-finger interdigitated sensor using a Voltera PCB printer. The sensor demonstrates exceptional performance when exposed to various loading and unloading pressures within the 0.2–500.0 kPa range. The results show a consistent correlation between the change in electrical resistance and the stress caused by the applied load. The ink is biodegradable in marine environments, which helps avoiding its accumulation in the ecosystem over time. [ABSTRACT FROM AUTHOR]

Electronics and mechatronics waste is an exponentially increasing environmental issue, especially for wearable devices, due to their widespread diffusion into society and short life cycle. To promote their enormous benefits (e.g., in assisting visually impaired individuals) in a sustainable way, biobased and/or biodegradable organic materials should be used instead of traditional components. This manuscript presents a multidisciplinary approach, which bridges materials science and mechatronics, to propose the first ECO‐friendly wearable vibroTACtile device (Eco‐Tac). The design of Eco‐Tac includes integration on a cotton t‐shirt through a novel biodegradable conductive ink forming electrical tracks, a flexible commercially available solar panel, and the vibrotactile haptic device itself. The ink comprises a green solvent, anisole, a soft polybutylene adipate terephthalate biodegradable binder, and conductive nanocarbon materials. The device case is a biodegradable biocomposite. As such, the feasibility of using a sustainable energy source to supply power to the device and the possibility of using biodegradable materials in its manufacturing are demonstrated. An experiment with 20 blindfolded subjects is conducted, reporting the device's potential for assistance in manipulation tasks. Overall, the results of this work represent the first significant step toward the creation of wearable and sustainable haptic devices with green electronics and mechatronics approaches. [ABSTRACT FROM AUTHOR]

The biodegradable electronics are on the rise, not just due to their role in medical implants, but also because of their eco‐friendly attributes. A variety of methods, including transfer printing, have been employed to integrate inorganic electronics onto biodegradable polymer substrates. However, the use of expensive materials, multiple intermediary steps, and labor‐intensive procedures can undermine their environment‐friendly benefits. Here, a straightforward yet efficient fabrication method is introduced for creating high‐performance biodegradable electronic devices. This method leverages the controlled adhesion between the biodegradable device and substrate using self‐assembled monolayers of octadecyltrichlorosilane. Mechanical and thermal analyses based on scratch tests and time‐domain thermoreflectance quantify the adhesion by adjusting the packing density of octadecyltrichlorosilane. Controlled adhesion allows the photolithography process without delamination while facilitating easy delamination during transfer printing. The authors demonstrate the direct fabrication of electronics consisted of inorganic materials (Mg, Zn, SiO2, Si nanomembrane) on wafers and transfer‐printing onto polymer substrates via a single transfer step. This streamlined approach enables wafer‐scale fabrication of biodegradable electronics, highlighting its potential for mass manufacturing. Pilot conceptual demonstration of mass‐produced edible hydration sensors and their application in salivation measurement through in vivo model show the potential capability of proposed fabrication method in the use of practical level. [ABSTRACT FROM AUTHOR]

Despite advances in soft, sticker‐like electronics, few efforts have dealt with the challenge of electronic waste. Here, this is addressed by introducing an eco‐friendly conductive ink for thin‐film circuitry composed of silver flakes and a water‐based polyurethane dispersion. This ink uniquely combines high electrical conductivity (1.6 × 105 S m−1), high resolution digital printability, robust adhesion for microchip integration, mechanical resilience, and recyclability. Recycling is achieved with an ecologically‐friendly processing method to decompose the circuits into constituent elements and recover the conductive ink with a decrease of only 2.4% in conductivity. Moreover, adding liquid metal enables stretchability of up to 200% strain, although this introduces the need for more complex recycling steps. Finally, on‐skin electrophysiological monitoring biostickers along with a recyclable smart package with integrated sensors for monitoring safe storage of perishable foods are demonstrated. [ABSTRACT FROM AUTHOR]

Green electronics made from degradable materials have recently attracted special attention, because electronic waste (e‐waste) represents a serious threat to the environment and to human health worldwide. Among the novel materials used for sustainable technologies, nanocelluloses containing at least 1D in the nanoscale range (1–100 nm) have been widely exploited for various industrial applications owing to their inherent properties, such as biodegradability, mechanical strength, thermal stability, and optical transparency. This review highlights recent advances in research on the development of patterns for conductive material on nanocellulose substrates for use in high‐performance green electronics. The advantages of nanocellulose substrates compared to conventional paper substrates for advanced green electronics are discussed. Importantly, this review emphasizes various fabrication strategies for producing conductive patterns on different types of nanocellulose‐based substrates, such as cellulose nanofiber (CNF), (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl(TEMPO)‐oxidized CNF, regenerated cellulose, and bacterial cellulose. In the latter part of this review, emerging engineering applications for green electronics such as circuits, transistors/antennas, sensors, energy storage systems, and electrochromic devices are further discussed. [ABSTRACT FROM AUTHOR]

A green textile‐based conductor with controllable electrical resistance change with deformation and transiency (i.e., dissolution in water) will be the holy grail in wearable electronics since it can satisfy divergent needs with a single solution and be sustainable simultaneously. Nevertheless, designing such material is challenging since opposite requirements shall be satisfied. To solve such a problem, cotton is functionalized using conductive inks made of graphene or carbon nanofiber, a biodegradable polyvinyl alcohol binder, and environmentally friendly solvents. The electrical resistance shows an anisotropic response to bending depending on the composition of the coating and the stress direction, functioning either as a deformable compliant electrode or a tunable piezoresistor. Indeed, it can withstand thousands of bending cycles with a change in resistance of less than 5% or change its resistance by many orders of magnitude with the same deformation thanks to the combination of cotton twill and different nanofillers. A simple modification in the binder composition adding waterborne polyurethane allows the coating to go from entirely transient in water within minutes to withstanding simulated washing cycles for hours without losing its electrical conductivity. This green versatile conductor may serve opposing needs by altering the material composition and the deformation direction. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) is gaining more and more popularity and it is establishing itself in all areas, from industry to everyday life. Given its pervasiveness and considering the problems that afflict today's world, that must be carefully monitored and addressed to guarantee a future for the new generations, the sustainability of technological solutions must be a focal point in the activities of researchers in the field. Many of these solutions are based on flexible, printed or wearable electronics. The choice of materials therefore becomes fundamental, just as it is crucial to provide the necessary power supply in a green way. In this paper we want to analyze the state of the art of flexible electronics for the IoT, paying particular attention to the issue of sustainability. Furthermore, considerations will be made on how the skills required for the designers of such flexible circuits, the features required to the new design tools and the characterization of electronic circuits are changing. [ABSTRACT FROM AUTHOR]

The growing usage and consumption of electronics‐integrated items into the daily routine has raised concerns on the disposal and proper recycling of these components. Here, a fully sustainable and green technology for the fabrication of different electronics on fruit‐waste derived paper substrate, is reported. The process relies on the carbonization of the topmost surface of different cellulose‐based substrates, derived from apple‐, kiwi‐, and grape‐based processes, by a CO2 laser. By optimizing the lasing parameters, electronic devices, such as capacitors, biosensors, and electrodes for food monitoring as well as heart and respiration activity analysis, are realized. Biocompatibility tests on fruit‐based cellulose reveal no shortcoming for on‐skin applications. The employment of such natural and plastic‐free substrate allows twofold strategies for electronics recycling. As a first approach, device dissolution is achieved at room temperature within 40 days, revealing transient behavior in natural solution and leaving no harmful residuals. Alternatively, the cellulose‐based electronics is reintroduced in nature, as possible support for plant seeding and growth or even soil amendment. These results demonstrate the realization of green, low‐cost and circular electronics, with possible applications in smart agriculture and the Internet‐of‐Thing, with no waste creation and zero or even positive impact on the ecosystem. [ABSTRACT FROM AUTHOR]

Increasing environmental concerns raised by the accumulation of electronic waste draws attention to the development of sustainable materials for short‐lived electronics. In this framework, printed capacitive humidity sensors and temperature resistive detectors composed exclusively of biodegradable materials: shellac, carbon‐derived particles, and egg‐albumin are reported. The sensor platform comprises interdigitated electrodes serving as a capacitive transducer for humidity sensing, and a serpentine used as a resistive temperature detector. Both the interdigitated and serpentine electrodes are manufactured by screen‐printing carbon ink on a shellac substrate. The humidity sensors are constructed by drop‐coating egg albumin on the interdigitated carbon electrodes and the temperature detector is prepared by encapsulating the serpentine design with shellac. Shellac is shown to be a biodegradable alternative to hydrophilic cellulose‐derived substrates, with the capacitive humidity sensors demonstrating a sensitivity of 0.011% RH−1. The response and recovery times on shellac are 12 and 20 times faster than on cellulose‐based substrate, and the serpentine resistive temperature detectors have a temperature coefficient of 5300 ppm K−1. At the end of their service‐life, the sensors produced are home compostable and can be environmentally friendly disposed, potentially enabling their future use for sustainable and environmentally friendly smart‐packaging, agricultural sensing, or point‐of‐care testing. [ABSTRACT FROM AUTHOR]

Sunflower‐inspired sun‐tracking systems have been arousing intensive investigations owing to their benefits to improve the efficiency of solar energy collection. Photodetector based on photosensitive semiconductors is a mainstream choice in the sun‐tracking system, which directs solar collectors always facing the sun. However, photosensitive semiconductors to date have usually hidden the disadvantages of environmental pollution after disposal. As for these problems, this work develops a green ionic liquid‐based photodetector, which displays reliable electrical feedback in response to sunlight. This liquid sunlight detector can be readily recycled with less laborious and costly operations. It obeys a light sensing mechanism of photothermal conversion, so it does not involve the problems related to dark current and light saturation. As a practical demonstration, the ionic liquid‐based photodetector is assembled into a sun‐tracking system, which successfully pursues the moving sun in a real time. When such a sun‐tracking system is in tandem with optical fiber concentrator, sunlight can be efficiently collected and transported to desired position. [ABSTRACT FROM AUTHOR]

Hydroxypropyl cellulose (HPC) is a commercially available and biodegradable cellulose derivative, which is known to self‐assemble into chiral nematic liquid crystal phases in water. These features, including liquid crystal‐induced selective reflections in the visible range, make HPC an ideal biopolymer host material for dynamic structural color‐shifting materials. Herein, HPC is used as a starting matrix material and found that, by adding carbon nanotubes (CNT) to an aqueous dispersion of HPC, the color saturation can be improved without influencing the structural color formation and simultaneously conferring electrical conductivity to the material. Additionally, up to 0.4 wt% of cellulose nanofibrils (CNF) can be added to control and tune the rheological properties of the suspension allowing for 3D printability while also maintaining the structural colors. The HPC‐CNT‐CNF printed composite materials show application for flexible color‐changing devices in the form of a dual readout optical and resistive strain sensor and is used as the active material in a dynamic seven‐segment color display. This multipurpose color‐changing material has the potential to be used in the creation of eco‐friendly visual intelligent devices and biodegradable user interfaces and, as such, contributes to the advancement of the field of sustainable and green electronics. [ABSTRACT FROM AUTHOR]

Electronic devices with biomaterials have paved a way toward "green electronics" to create a sustainable future. Memristors are drawing growing attention with integrated sensing, memory, and computing for future artificial intelligence applications. Biomaterial is an emerging class of memristive materials (the device is called as biomemristor) for transient and/or biodegradable purpose. Importantly, several unique features such as faithful synaptic behaviors, bimodal switching, and biovoltage operations are observed in biomemristors. Moreover, the biomemristors are suitable for human‐related applications due to the inherent biocompatibility of biomaterials and flexibility of the device with ultrathin thickness. These features make the biomemristors promising for biorealistic neuromorphic applications. Herein, the state of the art of biomemristors are comprehensively summarized and systematically discussed with particular attention on their unique biorealistic features. Challenges and prospects toward the further development of biomemristors are also provided and discussed. [ABSTRACT FROM AUTHOR]

TEMPO‐oxidized nanofibrillated cellulose (ONFC) with charged carboxyl groups is introduced for the efficient exfoliation of two‐dimensional (2D) MoS2/graphene composites. As an effective dispersant agent, ONFC can be easily absorbed between the adjacent layers, so as to prevent the accumulation of the exfoliated nanosheets. With the assistance of charged ONFC, the exfoliated MoS2/graphene is gradually increased in the aqueous dispersions with the elongated sonication time. After dewatering, self‐standing MoS2/Graphene/ONFC/CNTs composite films are rationally constructed using ONFC as flexible fibrous skeleton, and CNTs/graphene as 1D/2D interpenetrating electrical networks. Ultrathin MoS2 nanosheets anchored on the 1D/2D heterogeneous networks is directly acted as an ideal paper‐anode for lithium‐ion batteries (LIBs) without using traditional metallic current collector. The self‐standing flexible electrode materials based on natural cellulose will promote the future green electronics with high flexibility, miniaturization, and increased portability. [ABSTRACT FROM AUTHOR]

Edible electronics will facilitate point‐of‐care testing through safe devices digested/degraded in the body/environment after performing a specific function. This technology, to thrive, requires a library of materials that are the basic building blocks for eatable platforms. Edible electrical conductors fabricated with green methods and at a large scale and composed of food derivatives, ingestible in large amounts without risk for human health are needed. Here, conductive pastes made with materials with a high tolerable upper intake limit (≥mg kg−1 body weight per day) are proposed. Conductive oleogel composites, made with biodegradable and food‐grade materials like natural waxes, oils, and activated carbon conductive fillers, are presented. The proposed pastes are compatible with manufacturing processes such as direct ink writing and thus are suitable for an industrial scale‐up. These conductors are built without using solvents and with tunable electromechanical features and adhesion depending on the composition. They have antibacterial and hydrophobic properties so that they can be used in contact with food preventing contamination and preserving its organoleptic properties. As a proof‐of‐principle application, the edible conductive pastes are demonstrated to be effective edible contacts for food impedance analysis, to be integrated, for example, in smart fruit labels for ripening monitoring. [ABSTRACT FROM AUTHOR]

This article presents the realization of a bandpass filter on a flexible biopolymer substrate with a suitable fabrication process. We used copper adhesive tape and laser structuring to fabricate the filter based on a quasi‐lumped microstrip structure. The filter characteristics are a central frequency of 2.45 GHz, a bandwidth of 20%, and insertion loss of 1.2 dB. It is demonstrated that the filter's performance remains almost constant under different bending, folding, and rolling conditions. The results show that the proposed bio‐sourced polymer is a good candidate for flexible green electronics and wearable applications. [ABSTRACT FROM AUTHOR]

Monitoring soil moisture in real-time is an important parameter that helps farmers decide to enhance agriculture productivity and reduce resource wastage for better production and plant growth. In this work, we presented an easy-to-use and highly sensitive screen-printed flexible soil moisture sensor array to monitor soil moisture remotely for precision agriculture. The proposed sensor is based on a unique interdigitated electrode (IDE)-based capacitive structure with conductive carbon ink printed on a flexible polyethylene terephthalate (PET) substrate using the screen printing technique. Before soil moisture monitoring, the sensor is tested for humidity monitoring in an environmental chamber. A response of ∼144–1760 pF for 20–100%RH with 10%RH variation is observed for a single sensor, while an array configuration ranges from ∼127–1802 pF. The sensor response is observed for a temperature range from 20 to 50 'C. The sensor's sensitivity for relative humidity sensing is 19.123%pF/RH, and the response and recovery time are ∼3.3 s and ∼4.2 s. Further, the sensor is tested for soil moisture sensing, as moisture content is gradually added to the completely dry soil. A highly sensitive response for soil moisture content (MC) with a ∼40.7%pF/MC sensitivity is obtained. The sensor data is transmitted wirelessly using a Bluetooth module. The sensor is supported by a wooden stick, which illustrates the capabilities of biodegradability, the sensor is cost-effective and provides a real-time measurement for soil moisture. The sensors have the potential to provide maintenance-free monitoring, facilitating precise control of irrigation practices in precision agriculture. With their affordability and ability to operate on a large scale, the sensor offers promising opportunities for enhancing irrigation systems. [Display omitted] • A highly sensitive, printed, and flexible sensor's array is presented to monitor soil moisture content and humidity. • A unique IDE based design is proposed to enhance the sensor sensitivity which is important parameter for agriTech monitoring. • Response of the soil sensor array for given humidity is ∼144-1760pF, with sensitivity of 19.123%pF/RH. • The sensor illustrates cost-effectiveness and real-time soil moisture measurement capabilities for precision agriculture. • The soil moisture sensor enables maintenance-free monitoring, aiding precise irrigation control in precision agriculture. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dynamically adjustable mixed and layered hybrid films of nanocellulose and VO 2 nanoparticles were fabricated with simple filtration method. • Thermal and optical stimuli could be used to trigger a reversible change in electrical properties of the films. • Based on simulations, mixed films could be used for reconfigurable intelligent surfaces in 5G and 6G applications. • Layered films acted as smart, gradually switchable electromagnetic interference shields. • The films designed in this study open new possibilities for sustainable future wireless applications. The emerging fields of 5G and 6G telecommunication networks, Internet of Things, and artificial intelligence have intensified the demand for green nanostructured materials with adjustable and intelligent features that respond to external stimuli. By leveraging the insulator-to-metal transition of VO 2 nanoparticles, responsive composite films were developed by integrating these nanoparticles within a biopolymeric network of cationic cellulose nanofibers (CNF+). These films exhibit a reversible change in GHz permittivity upon exposure to thermal or optical stimuli, facilitating dynamic control of their electrical properties. The layered structure of the films further enhances their robustness, featuring a VO 2 nanoparticle core encased within CNF+ layers. This design not only strengthens the structure but also significantly boosts light-induced conductivity, particularly in layered variant, underscoring its potential in optoelectronic applications. Simulation studies reveal that the nonuniform, reconfigurable intelligent surface (RIS) of the developed mixed film adeptly manipulates incident electromagnetic waves, making it suitable for 5G/6G wireless signals. Conversely, the layered film serves as a switchable electromagnetic interference (EMI) shield, demonstrating notable differences in shielding efficiency between its hot and cold states. Consequently, CNF+/VO 2 composite films designed in this work emerge as a versatile, adaptable platform for intelligent electronics, particularly in the realm of 5G/6G wireless communications. [ABSTRACT FROM AUTHOR]

Biodegradable or eco‐degradable electronics is an emerging field of technology capable of reducing the excessively increasing electronic waste originating from the rapid development of personalized and bio‐integrated devices and skin adhesive patches. Through an advantageous solution process, biodegradable conductive pastes can be employed in various applications of soft and flexible devices. Herein a biodegradable conductive paste composed of molybdenum (Mo) microparticles and polybutylene adipate terephthalate (PBAT) exhibiting excellent mechanical flexibility and stretchability is reported, while also demonstrating substantially superior mechanical and conductive properties compared with previously reported biodegradable polymer matrices such as poly butanedithiol 1,3,5‐triallyl‐1,3,5‐triazine‐2,4,6‐(1H,3H,5H)‐trione pentenoic anhydride (PBTPA) and Candelilla wax (CW) owing to the significant elongation of PBAT. Moderate dissolution in phosphate buffer saline (PBS) accomplishes its full biodegradability and programmable lifecycle. Tetraglycol (TG) enhances elongation and conductivity performance by acting as a lubricant and improving the dispersion of microparticles. The practical implications of the Mo/PBAT pastes are demonstrated in numerous biodegradable electronic applications such as electrodes, strain and temperature sensors, joule heaters, interconnectors, and freestanding radiofrequency (RF) coils. [ABSTRACT FROM AUTHOR]

Eco‐friendliness is becoming an indispensable feature for electrical and electronic equipment to thrive in the competitive market. This comprehensive review is the first to define eco‐friendly electronics in its multiple meanings: power saving devices, end‐of‐life impact attenuators, equipment whose manufacturing uses green processing, electronics that use materials that minimize environmental and health risks, designs that improve lifespan, reparability, etc. More specifically, this review discusses eco‐friendly technologies and materials that are being introduced to replace the well‐established ones. This is done for all material classes (metals, polymers, ceramics, and composites). Manufacturing, recycling, and final product characteristics are discussed in their various interconnected aspects. Additionally, the concept of consciously planned obsolescence is introduced to address the paradoxical relationship between durability and efficiency. The overall conclusions are that there is an important global trend to make electronics more eco‐friendly. However, matching the performance and stability of well‐established materials and technologies seems to be the main barrier to achieve it. These new implementations can have detrimental or beneficial net impacts on the environment. Assessing their net outcome is challenging because their impacts are frequently unknown and the current evaluation methods (and tools) are incapable of comprehensively quantifying these impacts and generating reliable verdicts. [ABSTRACT FROM AUTHOR]

Plastic‐based electronics fill the gaps in conventional rigid silicon‐based devices toward the applications in soft interfaces. However, people in the future should also consider their potential environmental impact if tons of non‐degradable plastics are applied. Silk fibroin is a superior substrate alternative for the development of "green" electronics; whereas, the brittleness of silk films is still a major limitation impeding their practical use. Different from the widely reported polyphasic composite approaches, here a trace‐ion‐assisted plasticization strategy is developed, and shape‐engineerable pure silk fibroin paper (PSFP) is prepared for the first time, which can be engraved and crumpled like a sheet of paper in the dry state. The PSFPs exhibit higher tensile fracture energy (14.4 ± 4 kJ m−2) than any typical plastic‐electronic‐substrates as far as it is known. The intrinsic brittleness of pure silk films is overcome, and the PSFP can be easily engineered to form periodic meshes, electronic prototypes, and kirigami‐based devices, which are beyond the reported regenerated silk films or silk composite films. Moreover, the scrape coating method employed here is simple, highly repeatable, and suitable for scaled production of low‐cost PSFP continuously. Collectively, the PSFP is generalizable to various shapes and devices, represents an ideal substrate alternative to plastic electronics. [ABSTRACT FROM AUTHOR]

The production of electrical and electronic equipment is increasing worldwide with a dramatic increase of electronic waste. Sustainable materials to produce sensors may thus positively impact on the environment. Casein is a milk protein that was used to fabricate a non-cytotoxic and biodegradable capacitive sensor by a green chemical process adding glycerol and trehalose. The casein-based film was characterized by means of thermal (TGA and EGA-MS) and spectroscopic (FTIR-ATR and Dielectric Spectroscopy) techniques. Contact angle, water vapour transmission rate, cytotoxicity and biodegradability were also assessed. A PEDOT:PSS/reduced graphene oxide ink was produced and screen-printed onto the film surface to obtain electrically conductive electrodes. The dielectric properties of the casein-based film allowed for the fabrication of a capacitive sensor that proved sensitive to pH changes. [Display omitted] • Biodegradable and disposable capacitive sensor. • Non-cytotoxic protein-based material. • Novel protein-based dielectric material. • Green fabrication process. [ABSTRACT FROM AUTHOR]

Natural biomaterials are potential candidates for the next generation of green electronics due to their biocompatibility and biodegradability. On the other hand, the application of biocomposite systems in information storage, photoelectrochemical sensing, and biomedicine has further promoted the progress of environmentally benign bioelectronics. Here, we mainly review recent progress in the development of biocomposites in data storage, focusing on the application of biocomposites in resistive random-access memory (RRAM) and field effect transistors (FET) with their device structure, working mechanism, flexibility, transient characteristics. Specifically, we discuss the application of biocomposite-based non-volatile memories for simulating biological synapse. Finally, the application prospect and development potential of biocomposites are presented. [ABSTRACT FROM AUTHOR]

The rapid growth and adoption of microelectronics around the world has resulted in an increased awareness of potential environmental issues related to their use and disposal. Halogens, which have had various uses in microelectronics over the years, are known to emit toxic and corrosive gases during the disposal of electronic waste. Many organizations have applied pressure to the electronics industry to eliminate halogens completely (e.g., fluorine, chlorine, and bromine) from their products. Among the various efforts toward environmentally friendly products, making electronics completely halogen-free has gained significant attention, particularly in Asia and Europe. This initiative even impacts conformal coatings worldwide, on which most electronics rely for their long-term protection, reliability, and high performance against water and other corrosive harsh environments. Among the various coating options, the parylene family of conformal coatings offers beneficial properties to the microelectronics, improved over many properties offered by common epoxies, acrylics, urethanes, and silicones. Although parylene N is the only commercially available parylene that does not contain any halogens, its barrier performance against moisture and other corrosive chemicals is not quite as robust as the other parylenes. To meet the industry's current and future requirements, a new halogen-free parylene, ParyFree®, has been developed. This study introduces a new parylene type to the microelectronics industry and shares the characterization and qualification results of ParyFree® parylene conformal coating for the protection, reliability, and robust performance of microelectronics. Testing on the new coating includes IPX water resistance, corrosion resistance, and qualification per IPC-CC-830B. [ABSTRACT FROM AUTHOR]

In this paper, a water based All Dielectric Frequency Selective Surface (ADFSS) is presented made of renewable materials. This surface is based on a modified dielectric resonator incorporating air holes inside the water to increase its Q factor. The ADFSS shows a low pass response with a cutoff frequency of 3.7 GHz. The surface is simulated and measured giving reasonable results. [ABSTRACT FROM AUTHOR]

[Display omitted] • PEDOT:PSS/RCs substrate was fabricated for the development of green energy storage devices. • Vacuum-assisted filtration with a 3D printed shadow mask was used to create various conductive micropatterns on RC. • The MSC sandwich structure based on PEDOT:PSS/RCs exhibited good specific capacitance and cycling stability. Ecofriendly electronic and energy storage devices are critical for addressing the issues regarding the limited energy resources and environmental pollution. Conductive micropatterns on biodegradable substrates are key components for the development of green energy storage devices. In this study, we report a facile strategy for constructing highly conductive and flexible poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) micropatterns on regenerated cellulose (RC) substrates via a simple vacuum-assisted filtration with a 3D printed shadow mask and dimethyl sulfoxide (DMSO) post-treatment. The shadow mask was effectively used in a vacuum filtration process to create various PEDOT:PSS micropatterns on RC substrates (PEDOT:PSS/RCs). The RC substrates present the advantages of being both synthetic and natural polymers such as high uniformity, good solution-processability, mechanical property, and biodegradability. The PEDOT:PSS patterns on the RC substrates show a sheet resistance of 4.2 Ω/cm2, an electrical conductivity of 327 S/cm, good adhesion stability and excellent bending durability. Furthermore, the PEDOT:PSS micropatterns on the RC substrates were successfully used for fabricating a solid-state micro-supercapacitor (MSC) device. The MSC sandwich structure based on PEDOT:PSS/RCs has a good specific capacitance of 65.55 mF/cm2 and an excellent cycling stability over 4000 cycles. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Heterogenous bio-based films were made to be used in green electronics. • Cellulose nanofibrils, chitosan, magnetite and glycerol led to heterogenous films. • Incorporation of magnetite improved magnetic and electrical properties of the films. • Magnetite and glycerol combined enhances charge storage and insulative properties. Abstract The objective of this work was to prepare bio-based thin films and evaluate the additions of magnetite and glycerol on the physico-chemical (flexibility, wettability and barrier properties) and dielectric properties of cellulose/chitosan-based films. The films were prepared by solution casting and presented a suitable dispersion of the constituents observed by SEM and FTIR. The films were thermally stable up to 150 °C and had a higher flexibility, wettability and lower barrier properties upon addition of glycerol. The calculated dielectric constant (εr) for the composite films was based on measurements of capacitance, at 100 and 1000 Hz, with the additions of magnetite and glycerol more than doubling the εr increasing the charge storage capacity. The bio-based thin films have potential to be used as insulators in capacitors on the production of green electronics thus, reducing toxic and nonrenewable e-waste generation. [ABSTRACT FROM AUTHOR]

Abstract: Growing environmental awareness has prompted a paradigm shift toward using green materials for various electronic applications. Bio‐organic materials are promising candidates attributable to their inherent biocompatibility, biodegradability, and environmental friendliness. Here, a nonvolatile memory device based on resistive switching in a bio‐organic polysaccharides film is presented. The polysaccharides are extracted from natural Aloe vera gel using facile alcohol precipitation. Optimal film deposition is achieved through spin‐coating followed by drying at 120 °C, which is higher than the usual processing temperature of commercial Aloe vera gel. Both bipolar and unipolar resistive switching can be induced in the polysaccharides film depending on the top electrode of the device. A comprehensive elucidation of the switching mechanism reveals the existence of various conduction processes that are electronic, electrochemical, and thermochemical in nature resulting in the unique resistive switching behaviors. The device is capable of delivering competitive performances, featuring wide read memory windows and large ON/OFF ratios that render it with potential as a next‐generation nonvolatile memory. The demonstration represents an important milestone toward the realization of green electronics. [ABSTRACT FROM AUTHOR]

The Sn-Ag 3 . 0 -Cu 0 . 5 lead free solder ( LFS ) alloy is mostly used as good alternative as compared to conventional Tin-Lead ( Sn-Pb ) due to its good mechanical properties and no harmful effect on environment but it stills has some problems to be solved regarding the growth formation of intermetallic compounds ( IMCs ). The IMCs present inside the bulk tin ( Sn ) matrix grow at high temperature and hence their impact on mechanical properties becomes more significant. In this work the effects of lanthanum ( La ) doping of Sn-Ag 3 . 0 -Cu 0 . 5 is investigated as function of IMCs growth and mechanical properties including yield strength ( YS ) and ultimate tensile strength ( UTS ) under different thermal aging temperatures. The selected La concentration in this study is 0.4 wt%. The aging time is 50 h and thermal aging temperatures are 60 °C, 100 °C and 140 °C. The microstructure examination before and after thermal aging is observed using scanning electron microscopy ( SEM ) followed by image analysis to estimate the nature of IMCs . The chemical composition is confirmed with energy dispersive X-ray ( EDX ). The YS and UTS are also examined before and after thermal aging for the un-doped and doped samples from stress-strain curves using universal testing machine ( UTM ). It is investigated that inclusion of 0.4 wt% La into Sn-Ag 3 . 0 -Cu 0 . 5 solder system results in increasing the IMCs growth rate and hence mechanical properties reduced. It is also observed that the microstructure becomes coarsen after thermal aging due to growth of average IMCs particle size with significant decrease in YS and UTS . Further, mathematical relations with minimum error are developed to predict mechanical properties ( YS and UTS ) at various levels of aging temperature, showing a reciprocal relationship between aging temperature and mechanical properties. [ABSTRACT FROM AUTHOR]

Green Electronics In article number 2210422, by using a low‐cost CO2 laser on fruit‐based papers, Giuseppe Cantarella and co‐workers report the fabrication of green and biocompatible electronic devices. The employment of natural and plastic‐free materials gives rise to a sustainable and circular technology, allowing electronics recycling, with no waste creation, and reintroduction in nature. [ABSTRACT FROM AUTHOR]

Keywords: circular and sustainable electronics; flexible electronics; green electronics; healthcare; laser-induced electronics; papers EN circular and sustainable electronics flexible electronics green electronics healthcare laser-induced electronics papers 1 1 1 04/27/23 20230425 NES 230425 B Green Electronics b In article number 2210422, by using a low-cost CO SB 2 sb laser on fruit-based papers, Giuseppe Cantarella and co-workers report the fabrication of green and biocompatible electronic devices. Circular and sustainable electronics, flexible electronics, green electronics, healthcare, laser-induced electronics, papers The employment of natural and plastic-free materials gives rise to a sustainable and circular technology, allowing electronics recycling, with no waste creation, and reintroduction in nature. [Extracted from the article]

[Display omitted] • Aligned Ti 3 C 2 T x /CNF/PVA hybrid cryogels were prepared by freeze-drying. • Cell and surface structure of cryogels was manipulated by simple adjustments to freezing process. • The GHz and THz signal permittivity of cryogels was dominated by their surface structure. • The combination of designed bulk and surface layer could compensate even 20 wt % higher filler contents. • The produced green cryogels proved to be efficient in EMI shielding. Anisotropic, nanoporous structures are promising materials for manipulating the propagation of electromagnetic waves at millimeter and sub-THz frequencies as well as for electromagnetic interference (EMI) shielding with rapidly evolving green electronics. In this work, cell and surface architecture of sustainable hybrid cryogels of cellulose nanofibers, polyvinyl alcohol (PVA) and Ti 3 C 2 T X MXene was controlled to adjust their GHz and THz dielectric permittivity and EMI shielding performance. Temperature gradient freeze-drying was used to obtain aligned honeycomb and lamellar pore structures with specific surface layer designs. The millimeter wave permittivity varied relative to thickness direction as the side of cryogels that was directly exposed to cold gradient had systematically a higher permittivity. This anisotropy was caused by a thin, smooth outermost surface layer covering the open core structure. The surface designs of all cryogels dominated signal permittivity, and the effects of higher MXene dosages could be offset by the surface layer. Cryogels with dense surface layer containing 70 and 50 wt % of MXene displayed very high average attenuation levels of 52.1 and 37.2 dB, respectively. Overall, the results show that the structural design of porous hybrid material can be used to adjust their EMI shielding performance at GHz and THz frequencies. [ABSTRACT FROM AUTHOR]

This article presents a new approach for environmentally benign, low-cost batteries intended for single-use applications. The proposed battery is designed and fabricated using exclusively organic materials such as cellulose, carbon, and wax and features an integrated quinone-based redox chemistry to generate electricity within a compact form factor. This primary capillary flow battery is activated by the addition of a liquid sample and has shown continuous operation up to 100 min with an output voltage that can be conveniently scaled to match the voltage needs of portable electronic devices (1.5-3.0 V). Once depleted, the battery can be disposed of without the need for any recycling facility, as its components are nontoxic and shown to be biotically degradable in a standardized test. The practical utility of the battery is demonstrated by direct substitution of a lithium ion coin cell in a diagnostic application. [ABSTRACT FROM AUTHOR]

This paper presents a miniaturized Doppler radar that can be used as a motion sensor for low-cost Internet of things (IoT) applications. For the first time, a radar front-end and its antenna are integrated on a multilayer cellulose-based substrate, built-up by alternating paper, glue and metal layers. The circuit exploits a distributed microstrip structure that is realized using a copper adhesive laminate, so as to obtain a low-loss conductor. The radar operates at 24 GHz and transmits 5 mW of power. The antenna has a gain of 7.4 dBi and features a half power beam-width of 48 degrees. The sensor, that is just the size of a stamp, is able to detect the movement of a walking person up to 10 m in distance, while a minimum speed of 50 mm/s up to 3 m is clearly measured. Beyond this specific result, the present paper demonstrates that the attractive features of cellulose, including ultra-low cost and eco-friendliness (i.e., recyclability and biodegradability), can even be exploited for the realization of future high-frequency hardware. This opens opens the door to the implementation on cellulose of devices and systems which make up the “sensing layer” at the base of the IoT ecosystem. [ABSTRACT FROM AUTHOR]

One of the opportunities how to foster sustainability of public procurement is via purchasing goods and services taking into account balanced and integrated social, economic and environmental aspects while meeting the needs of public institutions. However, more exact methodological procedures are absent in the implementation of green public procurement. Such methodology could enable assessing the quality, quantification and significant connectivity to green and knowledge economy in current practice. Authors of the paper provide more exact methodology of green public procurement of goods and services based on its connectivity to the worldwide standardized indicators of sustainable socio-economic development as well as the results of their own research. [ABSTRACT FROM AUTHOR]

A new concept for reusable eco-friendly hydrogel electrolytes based on cellulose is introduced. The reported electrolytes are designed and engineered through a simple, fast, low-cost, and eco-friendly dissolution method of microcrystalline cellulose at low temperature using an aqueous LiOH/urea solvent system. The cellulose solution is combined with carboxymethyl cellulose, followed by the regeneration and simultaneous ion incorporation. The produced free standing cellulose-based electrolyte films exhibit interesting properties for application in flexible electrochemical devices, such as biosensors or electrolyte-gated transistors (EGTs), because of their high specific capacitances (4-5 µF cm−2), transparency, and flexibility. Indium-gallium-zinc-oxide EGTs on glass with laminated cellulose-based hydrogel electrolytes (CHEs) as the gate dielectric are produced presenting a low working voltage (<2 V), showing an on-off current ratio ( Ion/off) of 106, a subthreshold swing lower than 0.2 V dec−1, and saturation mobility (μSat) reaching 26 cm2 V−1 s−1. The flexible CHE-gated transistors on paper are also demonstrated, which operate at switching frequencies up to 100 Hz. Combining the flexibility of the EGTs on paper with the reusability of the developed CHEs is a breakthrough toward biodegradable advanced functional materials allied with disposable/recyclable and low-cost electronic devices. [ABSTRACT FROM AUTHOR]

There is a strong demand for flexible user interface technology with a desired size and shape to make real world objects touch-interactive. In this regard, plastic based touch sensors have been widely used on account of their adaptability. However, their fabrication involves eco-unfriendly procedures like lithography or other cleanroom processes which contribute greenhouse gases (GHG) and hence raises the need for exploring alternative green fabrication methods. In this work, we report the fabrication of an inexpensive, flexible, biocompatible, low power and environmentally benign interdigitated capacitive (IDC) touch sensor based on cleanroom-free and solvent-free processing of graphite on paper (GOP). The performance of touchpad with four touch sensor keys was evaluated by integrating it with Arduino UNO development board and it functioned similar to the conventional touchpads which are fabricated by utilizing complex procedures and expensive equipments on plastic substrates. The influence of the number and the overlap length of electrode digits on touch sensor performance was investigated and optimized based on variation in capacitance with the interaction of finger with the touch sensor for better performance and enhanced user experience. The pressure due to strength of the touch and strain induced due to bending and folding of the touch sensor resulted in insignificant variation in capacitance and no change in functionality. This suggests that the flexible and robust GOP based touchpad can be used in diverse applications such as user interface for medical diagnostics, health, environment and security monitoring devices where low cost, eco-friendly, flexible, durable and stable touch control is required. This approach of developing highly advanced, efficient yet biodegradable paper electronics which doesn’t involve the use of any toxic, flammable or corrosive gases nor chemicals paves the way for next generation green and sustainable eco-friendly electronics. [ABSTRACT FROM AUTHOR]

The recent emergence of materials for electronic systems that are capable of programmable self-destruction and/or bio/eco-resorption creates the potential for important classes of devices that cannot be easily addressed using conventional technologies, ranging from temporary biomedical implants to enviromentally benign environmental monitors to hardware secure data systems. Although most previous demonstrations rely on wet chemistry to initiate transient processes of degradation/decomposition, options in 'dry transient electronic systems' could expand the range of possible uses. The work presented here introduces materials and composite systems in which sublimation under ambient conditions leads to mechanical fragmentation and disintegration of active devices upon disappearance of a supporting substrate, encapsulation layer, interlayer dielectric and/or gate dielectric. Examples span arrays of transistors based on silicon nanomembranes with specialized device designs to solar cells adapted from commercial components. [ABSTRACT FROM AUTHOR]

In many revolutions of the cellulose based conductive materials, the most significant one was the developed material could be either directly used as a working electrode or used as the underlying substrate for the electrochemical deposition metal electrodes. In this work, an in situ polymerization of aniline monomer onto the porous structured cellulose scaffolds has been carried out, and then electrodeposition of Ag nanoparticles on the obtained conductive composites directly by using it as electrode. The Ag nanoparticles were deposited homogeneously on the matrix of polyaniline (PANI)/cellulose gels. The conductivity of PANI/cellulose nanocomposite gels containing Ag nanoparticles was increased to 0.94 S C m −1 , which was higher than that of pure PANI/cellulose composites (3.45 × 10 −2 S C m −1 ). Furthermore, it could be used as electrode for the supercapacitors, and the highest specific capacitance of the cellulose/PANI/Ag aerogels was 217 F g −1 . This approach offered a facile method for improving the electronic conductivity of native polymer nanohybrids, and suggested a new strategy for fabricating nanostructured polymer nanohybrids for application in energy storage. [ABSTRACT FROM AUTHOR]

This paper aims to demonstrate that novel additive manufacturing (AM) technologies like metal adhesive laminate and multilayer inkjet printing can be effectively exploited to fabricate high-performing radio-frequency passive components on flexible substrates. Both processes are substrate independent and therefore suitable for manufacturing circuits on several unconventional materials, such as photo-paper. In addition, their complementary features can be combined to develop a novel hybrid process. Proof-of-concept AM prototypes of passive components, such as capacitors and inductors, exhibiting quality factors over 70, never achieved before on paper, and self-resonant frequencies beyond 4 GHz are described. The maximum inductance and capacitance per unit area are 1.4 nH/mm2 and 6.5 pF/mm2, respectively. Moreover, an AM RF mixer with a conversion loss below 10 dB is demonstrated still on paper substrate. The mixer, fabricated with the copper adhesive laminate method, operates at 1 GHz and exploits a lumped balun transformer connected to two packaged diodes in series. [ABSTRACT FROM PUBLISHER]

[Display omitted] • A transient, biodegradable, biocompatible and recyclable hydrogel is developed. • Green synthesis of hydrogel with adhesion, self-healing and anti-freeze features. • The hydrogel with multi-signal detection for biomedical applications. • Eco-friendly triboelectric device for energy harvesting and medical nursing. Biodegradable or recyclable transient electronics originated from natural polymers are considered as significant solution for electronic waste (e-waste) management, sustainable development, and emerging implantable devices. Yet, they are mostly struggling from mismatched mechanical features with human tissue and inferior environmental adaptability. In this work, based on the novel covalent-like hydrogen bond engineering, we developed a syrup-modified gelatin/Ag-hydrogel, which is entirely derived from natural or safe constituents and highly stretchable, yet fully biodegrades or recyclable. Meanwhile, strong covalent-like hydrogen bonds endow it with several favorable features of adhesion, rapid self-healing and antifreeze. A series of multi-modal application scenarios are further demonstrated to verify the adaptability of this platform that integrates various attributes. Overall, this work provides the feasibility of modified natural polymers to replace synthetic polymers, and provides a general toolbox for the construction of functional units for "green electronics" and the expansion of application models. [ABSTRACT FROM AUTHOR]

Printed Structurally Colored Cellulose Sensors and Displays (Adv. Keywords: carbon nanotubes; direct-ink-writing; display; green electronics; hydroxypropyl cellulose; nanocellulose; structural color EN carbon nanotubes direct-ink-writing display green electronics hydroxypropyl cellulose nanocellulose structural color 1 1 1 01/12/23 20230101 NES 230101 B Direct-Ink-Writing b In article number 2200897, Gustav Nyström and co-workers present a biodegradable wood or cellulose derived ink system capable of giving vibrant stimuli tunable structural colors that can be extruded and 3D printed to complex materials and functional devices. Carbon nanotubes, direct-ink-writing, display, green electronics, hydroxypropyl cellulose, nanocellulose, structural color. [Extracted from the article]

ABSTRACT Transient Li-ion batteries based on polymeric constituents are presented, exhibiting a twofold increase in the potential and approximately three orders of magnitude faster transiency rate compared to other transient systems reported in the literature. The battery takes advantage of a close variation of the active materials used in conventional Li-ion batteries and can achieve and maintain a potential of >2.5 V. All materials are deposited form polymer-based emulsions and the transiency is achieved through a hybrid approach of redispersion of insoluble, and dissolution of soluble components in approximately 30 min. The presented proof of concept has paramount potentials in military and hardware security applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2021-2027 [ABSTRACT FROM AUTHOR]

[Display omitted] • Develop next generation green polymer composites in 2.5D/3D semiconductor packaging. • Interfacial connecting mechanisms related modified graphene have been demonstrated. • Polydopamine-graphene and cellulose nanofibers form 3D thermal transport network. • The modification related graphene fillers greatly enhance the thermal conductivity of epoxy. In this work, eco-friendly polydopamine (PDA) modifies graphene (PDA-G) through a π-π stacking interaction. Then, eco-friendly and biodegradable cellulose nanofiber (CNF) polymers are employed to combine with PDA-G to form a 3D thermal transport network. More significantly, their abundant functional groups, including hydroxyl groups and carboxyl groups, form interfacial hydrogen bonding with PDA-G to reduce the thermal interfacial resistance. With fundamental understanding of the interfacial engineering between CNF and PDA-G and with an effort to balance the effects of filler connection and thermal insulation of CNF, the resultant epoxy nanocomposites achieved a high through-plane thermal conductivity of 0.58 W/mK at only 3.05 wt% loading. In addition, the epoxy nanocomposites have a low CTE and high thermal stability. Meanwhile, the potential application of epoxy nanocomposites as thermal interface materials (TIMs) in semiconductor packaging has been demonstrated by both experimentations and simulation. These tests result in new pathways to design and modify fillers to meet the demands of next generation green polymer composites in 2.5D/3D semiconductor packaging. [ABSTRACT FROM AUTHOR]

This paper presents a flexible and wearable (on-body) dual band antenna operating in two Industrial, Scientific and Medical (ISM) frequency bands. The central frequencies selected are equal to 2.45 GHz and 5.8 GHz. In order to make the antenna suitable for Wireless Body Area Network (WBAN) applications, it is fabricated on a flexible biopolymer called cellulose laurate (CL). The proposed antenna, that has been designed and optimized on ANSYS HFSS, is realized using a process based on copper adhesive tape and laser structuring. The characterization of the antenna in terms of reflection coefficient, gain and radiation patterns shows a good agreement with the simulation data. Compared to state-of-the-art antennas, the investigated solution demonstrates competitive results. The proposed antenna also features stable performance under bending conditions and the estimated specific absorption rate (SAR) is well below the limits defined by international standards. All these results suggest that the proposed antenna is very well suited for potential wearable applications and is a step towards fully green electronics. [ABSTRACT FROM AUTHOR]

With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology--a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The goal of this study is to review the fundamental structures and chemistries of wood and wood-derived materials, which are essential for a wide range of existing and new enabling technologies. The scope of the review covers multiscale materials and assemblies of cellulose, hemicellulose, and lignin as well as other biomaterials derived from wood, in regard to their major emerging applications. Structure--properties-- application relationships will be investigated in detail. Understanding the fundamental properties of these structures is crucial for designing and manufacturing products for emerging applications. Today, a more holistic understanding of the interplay between the structure, chemistiy, and performance of wood and wood-derived materials is advancing historical applications of these materials. This new level of understanding also enables a myriad of new and exciting applications, which motivate this review. There are excellent reviews already on the classical topic of woody materials, and some recent reviews also cover new understanding of these materials as well as potential applications. This review will focus on the uniqueness of woody materials for three critical applications: green electronics, biological devices, and energy storage and bioenergy. [ABSTRACT FROM AUTHOR]