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The increasing use of electronic devices raises concerns about resource availability and end‐of‐life management, particularly regarding conductors for interconnects and sensing elements. While gold and silver are the leading materials for interconnects, they pose challenges related to scarcity, cost, and toxicity. Zinc offers a promising alternative due to its good electrical conductivity, non‐toxicity, abundance, and affordability. However, challenges in achieving high conductivity and waste generation from processing techniques like screen‐printing remain. To address this, a zinc ink optimizes for 3D printing is proposed, using active zinc particles in a shellac matrix. The methods, including chemical and photonic sintering, achieve conductivities of up to 8.74•104 S m⁻¹ on paper substrates, with stable performance over a range of 30%–70% relative humidity at 15, 20, 25, and 30 °C respectively. Potential applications in high‐conductivity transducers for humidity sensing and metal‐air batteries are demonstrated, achieving a maximum power output of 3.5 mW and an open‐circuit voltage of 1.25 V. The integration of digital material assembly of zinc, reliable high‐performance operation, and non‐toxicity pave the way for innovative advancements in sustainable electronics, including applications in environmental sensing, e‐textiles, and healthcare. [ABSTRACT FROM AUTHOR]

Developing materials for electronics and sensing based on abundant and degradable materials is fundamental for transitioning both fields toward a more sustainable future. In the long run, this approach can unleash these fields from using petroleum‐derived and/or scarce resources, possibly facilitating electronic waste (e‐waste) management at the same time. Starch, one of the most abundant and versatile natural polymers, has shown great potential in the fabrication of degradable/transient devices. In this work, electrically conductive and mechanically robust starch‐Ti3C2Tx MXene nanocomposites are successfully engineered, offering a promising advancement in sustainable electronics. The nanocomposite films exhibit remarkable tunability with varying MXene concentrations (from 0.69 to 2.42 vol%), allowing precise control over their properties. This tunability enables modifications in tensile strength (from 6.4 to 11.2 MPa), electrical conductivity (from 2.31 × 10−3 to 3.98 S m−1), and gauge factor. Such characteristics make these films ideal for various applications, including body movement monitoring, tactile sensing, handwriting recognition, and electronic smart skin. Unlike their petroleum‐based counterparts, the starch‐based films demonstrate significant biodegradability, breaking down within a month after being buried in soil. This rapid degradation highlights the potential of these transient composites for various electronics applications, offering an environmentally friendly alternative. [ABSTRACT FROM AUTHOR]

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]

Organic electroactive materials, particularly semiconducting polymers, are at the forefront of emerging organic electronics. Among the plethora of unique features, the possibility to formulate inks out of these materials is particularly promising for the large‐scale manufacturing of electronics at lower cost on a variety of soft substrates. While solution deposition of semiconducting materials is promising for developing printed electronics, the environmental footprint of the materials and related devices needs to be considered to achieve sustainable manufacturing. Towards the development of greener printed electronics, this work investigates the utilization of a non‐toxic, environmentally‐friendly solvent, namely branched polyethylene (BPE), to formulate semiconducting inks. Focusing on a diketopyrrolopyrrole‐based (DPP) semiconducting polymer, shellac as dielectric, and BPE as the solvent, solutions were prepared in different concentrations and their rheological properties were characterized. Then, printing on polyethylene terephthalate (PET) substrates using two different techniques was performed to fabricate organic field‐effect transistors (OFETs). Both printing techniques yielded OFETs with good performance and device characteristics, averaging approximately 10−2 and 10−4 cm2 V−1 s−1, respectively, for slot‐die coating and direct‐ink writing deposition. Notably, despite some difference in threshold voltages, OFETs produced via slot‐die coating and direct‐ink writing showed comparable charge mobilities to previously reported OFETs prepared from similar materials, particularly those prepared on silicon dioxide wafers. Overall, this work confirms the suitability of BPE to formulate semiconducting inks to develop printed electronics in a greener manner. The printing methodology developed in this work also open new avenues for the design of functional printed electronics and related technologies. [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]

Papertronics introduce a sustainable, cost‐effective revolution in electronics, especially for the Internet of Things. This research overcomes the traditional challenges of paper's porosity, which has impeded electronic component fabrication and performance. A novel approach that harnesses paper's natural capillary action, combined with hydrophobic wax patterning, to achieve precise vertical integration of electronic components is introduced. This method marks a significant departure from conventional surface deposition techniques. This study demonstrates the successful creation of tunable resistors, capacitors, and field‐effect transistors, embedded within a single sheet of paper. Contrary to previous assumptions that impeded the use of paper, its rough and porous texture as a strategic advantage, facilitating the precise fabrication of intricate electronic components is leveraged. Machine learning algorithms play an important role in predicting and enhancing the performance of these papertronic components. This innovation facilitates the development of compact printed circuit boards with increased circuit density, enabling the integration of diverse analog and digital circuits in either single or multi‐layer paper formats. The resulting papertronic systems exceed performance benchmarks, offering eco‐friendly disposal through biodegradability or incineration. These breakthroughs establish papertronics as a feasible, eco‐friendly alternative in the electronics industry, permitting widespread adoption and continuous innovation in sustainable electronic solutions. [ABSTRACT FROM AUTHOR]

Abstract The greener alternatives to tactile‐integrated multimodal sensors with self‐powered and self‐healing abilities are highly desirable for all‐in‐one autonomous sensing systems, particularly impressive in diverse application ranges including smart home, healthcare, and e‐skin. The dynamically self‐healable, stretchable piezoresistive sensors, and triboelectric nanogenerators (TENGs) reported herein are constructed by a facile, industrially viable method of grafting imidazolium ions on epoxidized natural rubber (ENR) backbone. Owing to cation‐π and π–π interaction between the percolated carbon nanotubes (CNTs)‐network and the imidazolium ions formed by non‐covalent interactions, the interfacial adhesion between the filler and elastomer is shown to improve considerably. The sensors show high piezoresistive strain sensitivity, reversible ionic network‐assisted self‐healability (efficiency ≈80%) and wide‐ranging detectability for precise monitoring of human movements. Both the healed and pristine sensors feature low hysteresis and stable electrical outputs over a wide strain range (≤200%). While achieving rapid self‐healing efficiency, the substrates are shown to exhibit remarkable robustness for harsh climates owing to significant mechanical toughness. Supported by excellent triboelectric tactile sensitivity (2.12 V N−1), the multifunctional TENG‐enabled sensor yields superior power density (0.16 mW cm−2). Moreover, the TENG module exhibits high force sensitivity and ease of operation that are considered versatile for all‐weather integrated tactile solutions for future technology.

Abstract 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 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

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 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 VO2 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 VO2 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+/VO2 composite films designed in this work emerge as a versatile, adaptable platform for intelligent electronics, particularly in the realm of 5G/6G wireless communications.

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]

With the increase in demand for low-carbon technology, green raw materials, and comfortable heating, academia and industry have paid considerable attention to cellulose-based electrothermal composites. This attention owes to the fact that cellulose is a versatile, abundant, low-cost, and sustainable material with beneficial properties. Here, we develop a novel strategy for fabricating flexible, transparent electrothermal heaters that are composed of both silver nanowire (AgNW)/poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) electrothermal composites and a regenerated cellulose (RC) matrix. The AgNWs were spin-coated onto glass substrates and easily transferred onto an RC surface through the coagulation and regeneration of the cellulose solution. PEDOT:PSS was coated onto the AgNW-coated RC matrix to improve the electrical and electrothermal properties of the film heaters. The PEDOT:PSS/AgNW/RC composite films demonstrated an excellent optical transmittance of 73.8% at 550 nm and a low sheet resistance of 11.2 Ω/sq. These composite heaters also exhibited a rapid heating response, uniform heat distribution, excellent heat generation, and robust structural stability. These electrothermal composites made from earth-abundant, low cost, and recyclable materials have great potential for green, flexible, transparent film heaters. [ABSTRACT FROM AUTHOR]

Sensors and transducers enable the robots' movements and interactions with humans and the environment. Particularly, tactile and motion sensors, even those inspired by the human skin, often miss many of its essential features. Indeed, the materials that constitute such sensors are often rigid and lack self‐healing and biodegradability. Furthermore, the large‐scale diffusion of these technologies propelled by robots spread in many aspects of the lives, from industrial to household settings, contributes heavily to the electronic and robotic waste problem. Recycling strategies for materials for robotics sensors are thus pivotal for future development. This work proposes self‐healable, recyclable, and biodegradable electrically conductive coatings. These coatings are based on conductive inks that combine graphene nanoplatelets and carbon nanofibers with a soft biodegradable vitrimer binder and are realized by spray coating. The use of the vitrimer ensures satisfying adhesion to diverse substrates, flexibility, conformability, self‐healing, and recyclability of the conductive coating. This material is a sustainable alternative to standard conductive inks for flexible electronics and soft robotics. Indeed, tests for the live monitoring of SoftHand3, the grasping system of many worldwide diffused robots, have yielded promising results. The use of biodegradable ingredients and the possibility of recycling makes it an appealing material to face the sustainability issue of today's electronics and robotics. [ABSTRACT FROM AUTHOR]

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.

Modern biosensors can provide real-time monitoring of individuals' health status, revolutionizing traditional healthcare diagnostics. As demand for these devices is continuously growing, the development of novel green materials and processes is mandatory to ensure sustainability. In this work, a simple laser direct writing approach was utilized to fabricate a novel green Laser Induced Graphene (LIG) glucose biosensor, whereby chitosan-based biofilms were used as writing feedstock material. Careful optimization of the biofilm composition was carried out in conjunction with the optimization of laser irradiation parameters to obtain bio-LIG structures with low sheet resistance and spectral characteristics of graphene-like materials. The surface of bio-LIG electrodes was modified with Prussian Blue nanoparticles and the electrocatalytic performance of bio-LIG sensors towards H2O2 was investigated using voltammetric techniques. The response of H2O2 was linear in the range 3 μM - 1 mM (sensitivity, 103.4 μA mM−1 cm−2 and the limit of detection (LOD), 1.9 μM). Following immobilization of glucose oxidase, the bio-LIG sensors showed a linear response of glucose in phosphate buffer (PBS) in the relevant physiological range of 25–300 μM (sensitivity, 457 nA mM−1 cm−2). The LOD was calculated as 9.6 μM. Additionally, the biosensor showed comparable results in artificial sweat.

In light of the growing concern for environmental protection and the alarming amount of waste produced due to hygiene regulations, this study suggests a biodegradable and eco-friendly solution that could make a significant contribution to the preservation of our planet. The developed solution was based on a polyhydroxybutyrate/polyhydroxyvalerate biopolymer, which has been tested regarding its physicochemical parameters and possible use in printed electrically conductive structures. Graphene nanoplatelets have been used as the conductive functional phase, due to literature reports of their potential use in biomedical applications and due to the potential of providing cytocompatibility in electrical structures by carbon nanomaterials. Prepared composites have been spray-coated onto PET film and paper substrates and then subjected to electrical, adhesion and optical measurements. In order to establish the conductivity of the developed composite, its resistance, layer thickness and surface topography were measured. Optical parameters have been specified using scanning electron microscopy (SEM) imaging and spectrophotometry. The conducted research opens a wide path for the use of the polyhydroxybutyrate/polyhydroxyvalerate biopolymer with graphene nanoplatelets in biomedical applications, ensuring good conductivity, biocompatibility and stability. [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]

Four pinaceae pine resins analyzed in this study: black pine, shore pine, Baltic amber, and rosin demonstrate excellent dielectric properties, outstanding film forming, and ease of processability from ethyl alcohol solutions. Their trap‐free nature allows fabrication of virtually hysteresis‐free organic field effect transistors operating in a low voltage window with excellent stability under bias stress. Such green constituents represent an excellent choice of materials for applications targeting biocompatibility and biodegradability of electronics and sensors, within the overall effort of sustainable electronics development and environmental friendliness. [ABSTRACT FROM AUTHOR]

Abstract Four pinaceae pine resins analyzed in this study: black pine, shore pine, Baltic amber, and rosin demonstrate excellent dielectric properties, outstanding film forming, and ease of processability from ethyl alcohol solutions. Their trap‐free nature allows fabrication of virtually hysteresis‐free organic field effect transistors operating in a low voltage window with excellent stability under bias stress. Such green constituents represent an excellent choice of materials for applications targeting biocompatibility and biodegradability of electronics and sensors, within the overall effort of sustainable electronics development and environmental friendliness.

Abstract 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.

Printing technologies have emerged as a viable method for the fabrication of various electronic components, including sensors, actuators, energy harvesters, thin-film transistors and circuits, as well as antennas. However, printing processes have limitations in terms of surface roughness and thickness. Printing conductive structures on novel substrates, such as cellulose-based sustainable paper, also leads to further challenges linked to the high surface porosity and ink carrier absorption. Herein, the variability of paper-based printed antenna performance due to different printing processes, ink carrier absorption, and temperature is investigated. The resonance frequency and gain of different printed antennas (e.g., screen, inkjet, and dispense-printed) are compared in terms of surface roughness, thickness, and resonance frequency. Screen-printed antennas show better performance compared to other printed antennas. The results show that the resonance frequency of antenna shifts 20, 30, and 50 MHz for screen printed, dispense printed, and inkjet printed respectively, from the nominal 2.6 GHz. In the case of the inkjet-printed antenna, a clear effect of skin depth is observed, due to the 0.91 μm thickness. Furthermore, it is demonstrated that the permittivity/dielectric constant of the paper substrate is significantly influenced by ink carrier absorption and temperature variance. [ABSTRACT FROM AUTHOR]

This article reviews the recent advances in the field of batteryless near-field communication (NFC) sensors for chemical sensing and biosensing. The commercial availability of low-cost commercial NFC integrated circuits (ICs) and their massive integration in smartphones, used as readers and cloud interfaces, have aroused great interest in new batteryless NFC sensors. The fact that coil antennas are not importantly affected by the body compared with other wireless sensors based on far-field communications makes this technology suitable for future wearable point-of-care testing (PoCT) devices. This review first compares energy harvesting based on NFC to other energy-harvesting technologies. Next, some practical recommendations for designing and tuning NFC-based tags are described. Power transfer is key because in most cases, the energy harvested has to be stable for several seconds and not contaminated by undesired signals. For this reason, the effect of the dimensions of the coils and the conductivity on the wireless power transfer is thoroughly discussed. In the last part of the review, the state of the art in NFC-based chemical and biosensors is presented. NFC-based tags (or sensor tags) are mainly based on commercial or custom NFC ICs, which are used to harvest the energy from the RF field generated by the smartphone to power the electronics. Low-consumption colorimeters and potentiostats can be integrated into these NFC tags, opening the door to the integration of chemical sensors and biosensors, which can be harvested and read from a smartphone. The smartphone is also used to upload the acquired information to the cloud to facilitate the internet of medical things (IoMT) paradigm. Finally, several chipless sensors recently proposed in the literature as a low-cost alternative for chemical applications are 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]

This article presents a NOT logic gate circuit based on a single memristor, and analyzes it for different biological memristive samples based on extracted resistances. The simple resistorvoltage representation of the memristor in the logic circuit is used to formulate a methodology to tune the parameters of the circuit in accordance with TTL voltage values. The logic circuit consists of two resistors in series with the memristor. The input is connected to one end of the memristor, and the output is drawn across the series connection of the second resistor, and the memristor. The methodology comprises of two steps, where, in the first step, the logic ‘low’ TTLinput voltages are examined, and in the second step, the circuit is evaluated for logic ‘high’ TTLinput voltages. The methodology reveals that there is a mínimum voltage value of ‘high’ TTL-input beyond which the output does not fall within the logic ‘low’ TTL-output. The proposed technique may be extended to evaluate novel memristive materials for single memristor-based NOT logic.

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 Ti3C2TX 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.

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]

[Display omitted] • Conceptualization and development of OleoPlast, the first oleogel-based bioplastic. • OleoPlast demonstrates versatile chemical, physical and mechanical properties. • OleoPlast is a biodegradable and recyclable thermoplastic. • OleoPlast is processable with injection/compression molding, CNC and FDM. • Applications include food packaging, electronics, composites and tissue engineering. The crisis of plastic waste highlights the urgent need for sustainable alternatives. Bioplastics are seen as a potential solution; however, challenges persist as many are still derived from petroleum, lack biodegradability, or fall short in essential properties such as mechanical strength, chemical stability, and ease of processing. This study pioneers the use of ethyl cellulose-based oleogels as bioderived and biodegradable thermoplastics. These groundbreaking bioplastics, obtained from renewable sources and waste oils, represent an environmentally friendly and high-performance alternative to traditional plastics. The bioplastic named OleoPlast is processed at temperatures ranging from 130 to 165 °C, utilizing different biobased oils and adjusting the oil-to-polymer ratio from 10:3.5 to 1:2. This process yields a high level of versatility, offering broad opportunities for customized applications in both research and industry. Remarkable stability under harsh environmental conditions and biocompatibility pave the way for the adoption of such bioplastics in biocomposite structures, food packaging, green electronics, and tissue engineering. Scalability is ensured by compatibility with both large-scale and high-resolution manufacturing processes, including injection and compression molding, computer numeric control (CNC) milling, and 3D fusion deposition modeling. Overall, this work lays the foundation for a new class of gel-state bioplastics, favoring the transition from traditional thermoplastics to sustainable options with vast perspectives of further exploration and customization in both laboratory and industrial environments. [ABSTRACT FROM AUTHOR]

Abstract The transition to a sustainable society is driving the development of green electronic solutions designed to have a minimal environmental impact. One promising route to achieve this goal is to construct electronics from biobased materials like cellulose, which is carbon neutral, non‐toxic, and recyclable. This is especially true for internet‐of‐things devices, which are rapidly growing in number and are becoming embedded in every aspect of our lives. Here, paper‐based sensor circuits are demonstrated, which use triboelectric pressure sensors to help elderly people communicate with the digital world using an interface in the form of an electronic “book”, which is more intuitive to them. The sensors are manufactured by screen printing onto flexible paper substrates, using in‐house developed cellulose‐based inks with non‐hazardous solvents. The triboelectric sensor signal, generated by the contact between a finger and chemically modified cellulose, can reach several volts, which can be registered by a portable microcontroller card and transmitted by Bluetooth to any device with an internet connection. Apart from the microcontroller (which can be easily removed), the whole system can be recycled at the end of life.

Nature and its biodiversity provide academics with a plethora of research topics, including the development of dielectric layers based on natural compounds that do not require any purification process for use in electronic equipments. Nevertheless, the properties of natural substances must then be investigated, and a suitable low-cost coating technique must be established. This study looks at the physicochemical behavior of khaya gum (KG) which is a biopolymer derived from khaya Senegalese tree exudates. In the form of powder, X-ray diffraction and scanning electron microscopy analyses of khaya gum revealed an amorphous structure and a slightly rough surface morphology with apparent wrinkles, respectively. The presence of oxides such as Al2O3, CaO, SiO2, as well as a high concentration of CuO, were disclosed by X-ray fluorescence data. Furthermore, tiny amounts of strontium, rubidium, molybdenum, chlorine, cadmium, and others elements were detected in KG. Several functionalities were qualitatively identified using Fourier Transform Infrared Spectroscopy. In the form of thin film, the absorption rate is low and the light transmittance exceeds 80%. The optical band gap was found to be around 4.15 eV. In regards of KG film dielectric properties, the capacitance frequency dependence exhibits conventional polar polymer dielectric behavior. At 1 kHz and room temperature, the estimated dielectric permittivity is between 6 and 10. These findings are intriguing, and they can be improved by combining different gum types for various applications in green opto-electronic systems. Highlights: A process was set up to deposit khaya gum films. Khaya film is found especially composed by copper, silicon and calcium oxides. A high optical band gap was deduced indicating high stability under illumination. Increasing temperature enhances conductivity and dielectric polarization. [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]

Triboelectric nanogenerators (TENGs) are a new class of energy harvesting devices that have the potential to become a dominating technology for producing renewable energy. The versatility of their designs allows TENGs to harvest mechanical energy from sources like wind and water. Currently used renewable energy technologies have a restricted number of materials from which they can be constructed, such as metals, plastics, semiconductors, and rare‐earth metals. These materials are all non‐renewable in themselves as they require mining/drilling and are difficult to recycle at end of life. TENGs on the other hand can be built from a large repertoire of materials, including materials from bio‐based sources. Here, a TENG constructed fully from wood‐derived materials like lignin, cellulose, paper, and cardboard, thus making it 100% green, recyclable, and even biodegradable, is demonstrated. The device can produce a maximum voltage, current, and power of 232 V, 17 mA m–2, and 1.6 W m–2, respectively, which is enough to power electronic systems and charge 6.5 µF capacitors. Finally, the device is used in a smart package application as a self‐powered impact sensor. The work shows the feasibility of producing renewable energy technologies that are sustainable both with respect to their energy sources and their material composition. [ABSTRACT FROM AUTHOR]

The surging demand for electronics is causing detrimental environmental consequences through massive electronic waste production. Urgently shifting toward renewable and eco-friendly materials is crucial for fostering a green circular economy. Herein, we develop a multifunctional bionanocomposite using an algae-derived carbohydrate biopolymer (alginate) and boron nitride nanosheet (BNNS) that can be readily employed as a multifunctional dielectric material. The adopted rational design principle includes spatial locking of superhigh loading of BNNS via hydrogel casting followed by layer-by-layer assembly via solvent evaporation, successive cross-link engineering, and hot pressing. We harness the hierarchical assembly of BNNS and the molecular interaction of alginates with BNNS to achieve synergistic material properties with excellent mechanical robustness (tensile strength ∼135 MPa, Young's modulus ∼18 GPa), flexibility, thermal conductivity (∼4.5 W m -1 K -1 ), flame retardance, and dielectric properties (dielectric constant ∼7, dielectric strength ∼400 V/μm, and maximum energy density ∼4.33 J/cm 3 ) that outperform traditional synthetic polymer dielectrics. Finally, we leverage the synergistic material properties of our engineered bionanocomposite to showcase its potential in green electronic applications, for example, supercapacitors and flexible interconnects. The supercapacitor device consisting of aerosol jet-printed single-walled carbon nanotube electrodes on our engineered bionanocomposite demonstrated a volumetric capacitance of ∼7 F/cm 3 and robust rate capability, while the printed silver interconnects maintained conductivity in various deformed states (i.e., bending or flexing).

The growing demand of disposable electronics raises serious concerns for the corresponding increase in the amount of electronic waste, with severe environmental impact. Organic and flexible electronics have been proposed long ago as a more sustainable and energy-efficient technological platform with respect to established ones. Yet, such technology is leading to a drastic increase of plastic waste if common approaches for flexible substrates are followed. In this scenario, biodegradable solutions can significantly limit the environmental impact, actively contributing to eliminate the waste streams (plastic or electronic) associated with disposal of devices. However, achieving suitably scalable processes to pattern mechanically robust organic electronics onto largely available biodegradable substrates is still an open challenge. In this work, all-organic and highly flexible field-effect transistors, inkjet printed onto the biodegradable and compostable commercial substrate Mater-Bi, are demonstrated. Because of the thermal instability of Mater-Bi, no annealing steps are applied, producing devices with limited carrier mobility, yet showing correct n-type behavior and robustness to bending and crumpling. The degradation behavior of the final system shows unaltered biodegradability level according to ISO 14851. These results represent a promising step toward sustainable flexible and large-area electronics, combining energy and materials efficient processes with largely available biodegradable substrates.

Abstract Triboelectric nanogenerators (TENGs) are a new class of energy harvesting devices that have the potential to become a dominating technology for producing renewable energy. The versatility of their designs allows TENGs to harvest mechanical energy from sources like wind and water. Currently used renewable energy technologies have a restricted number of materials from which they can be constructed, such as metals, plastics, semiconductors, and rare‐earth metals. These materials are all non‐renewable in themselves as they require mining/drilling and are difficult to recycle at end of life. TENGs on the other hand can be built from a large repertoire of materials, including materials from bio‐based sources. Here, a TENG constructed fully from wood‐derived materials like lignin, cellulose, paper, and cardboard, thus making it 100% green, recyclable, and even biodegradable, is demonstrated. The device can produce a maximum voltage, current, and power of 232 V, 17 mA m–2, and 1.6 W m–2, respectively, which is enough to power electronic systems and charge 6.5 µF capacitors. Finally, the device is used in a smart package application as a self‐powered impact sensor. The work shows the feasibility of producing renewable energy technologies that are sustainable both with respect to their energy sources and their material composition.