Consumer electronics have caused an unsustainable amount of waste electrical and electronic equipment (WEEE). Organic electronics, by means of eco-design, represent an opportunity to manufacture compostable electronic devices.

Waste electrical and electronic equipment (WEEE), or e-waste, is defined as the waste of any device that uses a power source and that has reached its end of life. Disposing of WEEE at landfill sites has been identified as an inefficient solid waste processing strategy as well as a threat to human health and the environment. In the effort to mitigate the problem, practices such as (i) designing products for durability, reparability, and safe recycling, and (ii) promoting closed-loop systems based on systematic collection and reuse/refurbishment have been identified. In this perspective, we introduce a complementary route to making electronics more sustainable: organic electronics based on biodegradable materials and devices. Biodegradable organic electronics lie at the intersection of research in chemistry, materials science, device engineering, bioelectronics, microbiology, and toxicology. The design of organic electronics for standardized biodegradability will allow composting to be an end-of-life option.

Lack of data on available agriwaste by type of source, local variations in agricultural consumption, and the uncertain feasibility of industrial scaling, all contribute to the challenges of developing commercially viable agriwaste-to-resource building products. Materials Passports linked to Building Management Information systems are tools that can improve regional planning efforts and the coordination of sustainable supply chains focused on new product development and product stewardship.

Globally, an estimated 3.5 kg per capita of daily agricultural waste is transferred to municipal landfills. Stated differently, 7.8 billion people generate 26.25 billion kg of daily agriwaste. Numerous studies established linkages between leachates from solid waste landfills, bioaccumulation of toxic chemicals, and greenhouse gas emissions that are a leading cause of climate change. Furthermore, raw material scarcity threatens to constrain economic growth and productivity. Sustainable circular economy practices focus on increased efficiency and a decoupling of wasted natural resource consumption from economic growth. Academic and industry researchers are focused on developing circular economy solutions that increase resource efficiency while decoupling wasted natural resource consumption from economic growth. Human acceptance and adaptation of technology are ideologically, culturally, and socio-technically dependent. Waste banana peels are used as an analytical scenario of how BIM modeling can improve the production of localized, affordable, and culturally appropriate building materials. Ideological and cultural norms are a precursor for socio-technical acceptance. Building material selection is examined from the perspective of complex factors creating uncertain economic valuations, and socio-cultural variations in the definition of waste. The objective of the research is to open multidisciplinary examination of the practices and choices that determine affordably safe building materials.

Eumelanin is a redox active, quinone-based biopigment, featuring a broad band absorption in the UV-Vis region. The combination of the redox and optical properties makes eumelanin an interesting candidate to explore light-assisted storage technologies. Electrodes of melanin on indium tin oxide (ITO) current collectors were investigated for their morphological and voltammetric characteristics in aqueous electrolytes. Under solar light, we observed that the capacity and the capacitance of the melanin electrodes significantly increase with respect to the dark conditions (by 63% and 73%, respectively).

Regular WO3 nanocubes have been prepared on a large scale through a convenient hydrothermal route at the temperature of 200 °C. The products were characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy, UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. A crystal growth process for WO3 nanocubes was simply proposed based on the comparative experiments. The band gap energy (Eg) was determined to be 2.58 eV based on the UV-vis DRS analysis, and the PL spectrum exhibited a strong blue light emission band centered at 469 nm. The as-prepared WO3 nanocubes showed higher visible light photocatalytic performance for degrading rhodamine B compared with WO3·H2O and WO3·0.33H2O/WO3 which were obtained at 80 °C and 140 °C, respectively, suggesting potential application in the region of wastewater purification.

Wave energy converters have been developed and commercialized in past decades; they have now faced numerous challenges of large volume sizes, environmental hazards, and high costs of deployment, components and maintenance. To address these challenges and make a wave energy converter practically available for various applications at a reasonable cost, we have developed a soft wave energy harvester that integrated low-cost soft material structures and piezoelectric-based Macro Fiber Composite (MFC). This integrated soft wave energy converter has a straightforward fabrication process and structure that can harvest energy from a broad working frequency of waves. The innovative design combined low-cost and commercially available materials and formed a harvester that addressed the aforementioned problems of commercially available harvesters. Additionally, the low cost and simple design are scalable for large energy conversion in the future. The energy conversion performance of the proposed platform has been investigated in a wave flume with low-frequency incoming waves (<2Hz). The soft energy conversion platform is hung like a curtain and produces a maximum 487nW. Also, the low cost and durable encapsulation can protect the electrical properties of MFCs and circuits, and a single harvester can last through all experiment steps without any degradation, which was more than 170 hours.

One of the most promising methods to produce graphene in large scale is the use of chemical exfoliation together with chemical reduction to achieve reduced graphene oxide. Replacing conventional reducing agents, such as NaBH4 and hydrazine, with cheap, widely available, safe, environmentally friendly, and easy-to-prepare reducing agents is a key to large-scale commercial production of reduced graphene oxide. In this work, we investigate the effectiveness of utilizing fruit extracts derived from banana peel and juice to reduce graphene oxide. After the reduction, the oxygen-containing functional groups in graphene oxide are effectively removed, and the sp2 hybridized carbon-carbon bonding networks are restored, as evidenced by the characterization using x-ray photoelectron spectroscopy and Raman spectroscopy. Our banana extracts would offer a promising pathway for realizing cheap, safe, and environmentally friendly reducing agents for the upscale production of reduced graphene oxide.

There is a huge variety of modular product designs for smartphones (concept studies, prototypes, products on the market), and a similarly high variety of circular economy aspects related to these different design approaches. Modularity requires initially more material input but pays off as the consumer is embracing the possibilities of modularity. Key materials for modularity features are gold, beryllium, and neodymium, etc.

On the example of smartphones modularity as a strategy for circular design is analyzed in detail. Modularity of products is a design trend, which is supposed to facilitate reparability, recyclability, and/or upgradeability. However, modularity requires some design changes. The most evident design change is the need for connectors to provide mechanical and electrical contact between individual modules. Depending on the nature and use scenario of a connector reliability, robustness, wear resistance, and non-reactive surfaces are required. The paper explains different modularity approaches for smartphones, some of these being already available in the market, others are still in a conceptual phase. Analyzing technologies for modularity leads to a group of “modularity materials,” which are essential for such circular design approaches, but at the same time are among those materials with a large environmental footprint or limited recyclability. A life cycle assessment of a modular smartphone shows a roughly 10% higher environmental life cycle impact compared with a conventional design. This needs to be compensated by reaping the circular economy benefits of a modular design, i.e., higher likeliness of getting a broken device repaired, extending the lifetime through hardware upgrades and refurbishment.

The aim of this investigation was to study castor, canola, and sesame vegetable oils in order to evaluate their potential use as lubricants in steel mechanical components. For this purpose, densities of each oil were evaluated using the pycnometer method, as well as their dynamic viscosities through a Brookfield DV-II rotational viscometer. Both properties were evaluated at temperatures of 25, 40 and 100 °C. Additionally, viscosity indexes were determined according to ASTM D 2270. These rheological properties were used to estimate the lubrication regime considering parameters of real contact conditions in mechanical components. Friction and wear analyses were carried out to investigate the behaviour of the vegetable oil as lubricants. Such tests were carried out at room temperature on a CSM tribometer with pin-on-disk configuration by using castor, canola and sesame oils as lubricants. AISI 4140 hardened steel against AISI 100Cr6 steel pin was used as a mechanical component. From the rheological study, it was observed that canola and sesame oils behave as dilatant fluids at the evaluated temperatures, while castor oil behaves like a Newtonian fluid at 25 and 40 °C. Castor oil showed the highest density value among oils studied, but it also exhibited the lowest value of viscosity index (271). Contrarily, sesame oil was the least dense, but it exhibited the highest viscosity index (545). On the other hand, the lubrication regime study showed that by using castor oil as a lubricant in the mechanical component (4140/100Cr6), the system worked in a mixed lubrication regime while by using canola and sesame oils the system operated in boundary lubrication conditions. Finally, the kinetic friction coefficients were different for each lubricant obtaining the lowest value with castor oil while the highest value of friction coefficient was exhibited by the sesame oil lubricant.

Solar water splitting can potentially play a significant role in the future, sustainable and carbon-neutral energy infrastructure - by generating hydrogen as a green fuel from renewable sources and liquid-fuels via carbon-dioxide reduction. Hydrogen has higher gravimetric energy-yield compared to most of the conventional fossil fuels, is storable and transportable on demand. With the prospective green hydrogen economy in mind, considerable efforts have been made in the quest for a stable and efficient photocatalyst/photoelectrode which can eventually lead towards the realization of large-scale hydrogen production system. This snapshot review provides a summary of the basic principles and challenges associated with unassisted overall water splitting, and highlights the recent technological advancements made on the device and system designs on lab-scale - to improve different performance metrics, i.e., efficiency, stability, scalability and large-scale prototypes with demonstrated potentials for future developments.

Ultra deep desulfurization of liquid fuels such as gasoline/diesel has attracted considerable attention of modern clean fuel research due to strict environmental regulations. Apart from that, SOx produced during combustion, poison the catalytic converter and exhaust emission system. Comparing to conventional catalytic and hydrodesulfurization techniques, adsorptive method for removal of sulfur bearing compounds e.g. thiophene derivatives is a promising approach which does not require hydrogen gas and high temperature. In this study, we used nickel sulfide nanoparticles incorporated poly(methyl methacrylate)-zirconia membranes as potential affinity material for adsorptive extraction of dibenzothiophene from n-hexane. The functionality and surface morphology of synthesized material was examined by Fourier transformation infrared (FTIR) spectroscopy and atomic force microscopy (AFM) images, respectively. The quantitative data regarding adsorptive removal of dibenzothiophene was determined by monitoring the shift in absorbance values of standard solutions before and after treating with synthesized material under ambient conditions. Nickel sulphide nanoparticles exhibited suitable rebinding response for removal of dibenzothiophene down to 1 ppm due to affinity interactions which is useful concerning ultra deep desulfurization. Finally, nickel sulphide nanoparticles were incorporated in poly(methyl methacrylate)-zirconia membrane which showed potential application for adsorptive desulfurization of dibenzothiophene at ambient conditions.

The micro-nano rough structure promotes the formation of superhydrophobic surfaces, while the formation of superoleophobic surfaces requires the support of re-entrant structures. Electrochemical etching and boiling water treatment methods were used to process the superoleophobic surface in the Al–Mg alloy substrate. The differences between the potential of the aluminum and the magnesium promoted the formation of the surface microstructure under the current stimulation, and the surface was formed into dense nanoscale needle-like coating after boiling water treatment. Scanning electron microscopy, energy dispersive spectroscopy, and contact angle measurement were performed to characterize the morphological features, chemical composition, and surface wettability, respectively. The so-prepared superoleophobic surfaces showed high contact angles and small sliding angles for water, ethylene glycol, and hexadecane. In addition, surface topography, reaction mechanism, and experimental parameters were also studied.

Sputtered lead-free piezoelectric materials like potassium sodium niobate (K1-xNaxNbO3 or KNN) have received significant technological interest in recent years in light of several reports of piezoelectric constants comparable to lead zirconium titanate (PZT). Potential applications include self-powered sensors, actuators, and low acoustic impedance transducers. For large area printed applications, it is vital to develop low-temperature solution processed deposition methods. In this work, sol-gel synthesis of K-rich (70:30) KNN was carried out under an argon atmosphere, using acetate precursors, followed by precipitation of white KNN powder upon careful drying. Powder X-ray diffraction (XRD) scans of the product with a Cu Kα source after calcination revealed a dominant (110) peak, accompanied by smaller (100) and (010) peaks, in agreement with published standard KNN data. The composition of K-rich phase was confirmed using energy dispersive X-ray spectroscopy (EDX). To produce thin films, the sol was spin coated on a surface-treated Au-coated Si substrate, followed by slow annealing to obtain low surface roughness films (RMS roughness ﹤∼10 nm) of thickness ∼200 nm after solvent removal. Atomic force microscopy (AFM) scans revealed an unremarkable amorphous film. However, deposition of the sol on the Au-coated backside of Si wafer under similar processing conditions revealed limited polycrystalline film formation observed using optical profilometry. Thin film XRD measurements of the deposited film reveal orthorhombic phase growth of KNN, though the unannealed film was more amorphous than the calcined KNN film. Preliminary piezoresponse force microscopy (PFM) scans were used to estimate a piezoelectric constant (d33) ∼ 2.7 pC/N, consistent with the general expectation of lower piezoelectric constants for thin sol-gel films. The highest processing temperature used at any step during the deposition process was 90°C, consistent with the applications involving flexible polyimide substrates. This low-temperature thin-film growth suggests a potential route towards integration of large area piezoelectric generators for environmentally-friendly autonomous flexible sensor applications, with better control of phase and composition during the solution-phase deposition of KNN.

Fusion energy is one of the options to contribute to the energy demand of future generations without adding to global warming. In this paper, we present the status of fusion energy research on the basis of magnetic confinement.

Fusion energy is one of the options to contribute to the energy demand of future generations without contributing to global warming. In this paper, we present the status of fusion energy research on the basis of magnetic confinement. In France, the first fusion reactor ITER is under construction. Its success will be measured on the expectation to deliver 500 MW thermal power—a factor of 10 above the power to maintain the energy producing process. ITER is based on the tokamak concept. In addition, Wendelstein 7-X, an ambitious stellarator, has recently started operation. Both confinement concepts—the tokamak and the stellarator—will be discussed along with general topics regarding fusion technology, operational safety, fusion waste, possible electricity costs, and roadmaps toward a fusion reactor as a power source.

Soiling in solar power generation will be a significant obstacle to its growth if a water free method cannot be found. Demand for water in arid regions will increase as more solar power generation is built, requiring more water to clean the optical surface, in turn increasing the price of water. This will lead to increased operating costs for solar power generation, and potentially disputes in locations where water is scarce. The electrodynamic screen (EDS) can reduce soiling and contribute to restoring the optical surface without the use of water. Periodic cleaning will still be required, but at reduced frequency, leading to a significant reduction in the consumption of water. In this model, it was found that a 250 MW concentrated solar power plant would have a 74% reduction in water given current laboratory production uncertainties. This indicates that EDS technology could decrease both the operating cost and the water use for solar generation plants.

The use of natural materials in paper and textiles, and in support of tunable and mechanically robust systems for sensing toxic gases, removing pollutants from water, and constructing functional biodegradable scaffolds, is a topic of great scientific and practical importance. The social, environmental, and economic impact of using natural materials to functionalize integrated systems for new designs is imperative, as the need to reuse and recycle natural resources has increased in current manufacturing. The inclusion of sustainability in the design of new materials and processes is almost a common practice; concurrently, the usage of “being more sustainable” is becoming a more conjointly used term in urban conversations. That said, systems integration and natural materials are intrinsically related to produce novel materials that can function as sensors, switches, platforms, and building blocks in a sustainable fashion. The contributions in this issue of MRS Bulletin highlight the importance and benefits to society that systems integration of functional materials can provide.

The carbon dots were investigated to reveal their light-emitting mechanism. The fluorescence spectra of carbon dots show typically two different types of photoluminescence: the excitation-independent component in the short wavelength, and the excitation-dependent component in the longer wavelength. The UV-Vis spectrum of carbon dots shows the absorption maximum of 340 nm which should be accredited to the n-π* transition of the carbonyl group in carbon dots. Absolute quantum yields of carbon dots dispersed in Polyvinyl alcohol is around 15% when the excitation wavelength is less than 425 nm, but decreases continuously when the excitation wavelength increases. The decay lifetimes of the carbon dots also show an abrupt change at excitation wavelength 425 nm. Time resolved photoluminescence was implemented from 31K to 291K to study the photoluminescence decay dynamics of carbon dots, resulting in the continuously decreasing of the lifetime as the temperature increases.

A new lab-based aerosol jet fog (ajFOG) deposition system with an atomizer consisting of two opposing jets located within the deposition chamber is introduced and its capabilities are examined. The unique opposing configuration of the atomizer enables the formation of a highly uniform fog even from low volatility precursors. Aluminum oxide phosphate (AlPO) thin films were deposited onto Si wafers at room temperature and sub-atmospheric pressure by using an aqueous precursor. Films were characterized by spectroscopic ellipsometry, x-ray diffraction and reflectivity, scanning electron microscopy, and metal/oxide/semiconductor (MOS) capacitor electrical measurements. Film thickness uniformity, density, surface roughness, and charge transport mechanisms were found to be comparable to spin-coated thin films deposited using the same precursor, demonstrating the effectiveness of this aerosol technique. A process model was developed to predict film thickness as a function of precursor concentration, exposure time, fog settling time, and number of exposures.

Recent advancement of inorganic dissolvable electronics nucleates around a realization that single-crystal silicon nanomembrane undergoes hydrolysis in biologically relevant conditions. The silicon-based high-performance dissolvable electronic devices are initially conceived for biomedical implants that function for a programmed timeframe followed by a complete dissolution to eliminate the need for recollection. The technology developed for biomedicine also presents unique opportunities in security devices that physically destruct and in environmentally benign electronics that dissolve without a trace to reduce electronic wastes. The new class of devices with this emerging technology complements the existing efforts in organic biodegradable devices. Compatible with state-of-the-art fabrication facilities for commercial microelectronics, the technology has a huge potential for future commercialization. This mini review will first discuss the relevant materials for the inorganic dissolvable electronics and then present the demonstrated applications in functional devices, followed by a perspective for the future developments.

DNA-immobilized Fe3O4 particles (DNA–Fe-particles) were prepared by mixing DNA, magnetic Fe3O4 particles, and the silane coupling reagent, bis[3-(trimethoxysilyl)propyl]amine. The DNA–inorganic hybrid material was uniformly immobilized onto magnetic Fe3O4 particles with the diameters of approximately 450 nm. These DNA–Fe-particles were stable in water. Additionally, we could simply collect the DNA–Fe-particles by a magnet from an aqueous solution. Therefore, we demonstrated the accumulation of various metal ions, such as heavy and rare-earth metal ions, by the DNA–Fe-particles. As a result, although these DNA–Fe-particles could selectively accumulate heavy and rare-earth metal ions, these materials could not accumulate the light metal ions, such as Mg(II) and Ca(II) ions. Furthermore, the metal ion-accumulated DNA–Fe-particles could be recycled by washing them with an aqueous ethylenediaminetetraacetic acid solution.

In this work, we studied the synthesis of biodegradable copolymers of the type poly(isobutyl vinyl ether)-co-(ε-caprolactone) (PIBVE-co-PCL) using a homogeneous mono-cyclopentadienyltitanium catalyst and methylaluminoxane (MAO) as co-catalyst. These copolymers can also be used as plasticizers for flexible poly(vinyl chloride) (PVC), improving its thermal properties. The copolymer PIBVE-co-PCL could be synthesized with a high conversion (>90%). The use of 39 wt.% of the copolymer in the formulation of PVC decreases its glass transition temperature (Tg) by -6.51 °C. By varying the copolymer composition it is possible to obtain PVC with different Tg values that could be used for different applications. A particular application where one could use this type of copolymer is in PVC formulations for the fabrication of blood bags. The toxicity of dioctyl phthalate (DOP), which is the more commonly used plasticizer for PVC, limits the use of these formulations for the mentioned purpose. The PVC plasticized with the biodegradable copolymer showed an increase in the degradation temperature, improving the thermal stability of the PVC formulation in comparison with the phthalates usually used as plasticizers.