Water-gated field-effect transistors (WGFETs) are promising platforms for chemical sensing due to their high sensitivity to interfacial electrochemical processes. In this work, we report a ZnO-Ag nanocomposite semiconductor layer deposited by spray coating onto interdigitated electrodes and operated as a water-gated transistor for the detection of indigo dye in aqueous media. The incorporation of Ag nanoparticles improves interfacial charge transfer and adsorption interactions with the analyte. Electrical characterization demonstrates stable transistor operation below 1.5 V and current modulation exceeding four orders of magnitude. Adsorption of indigo molecules at the semiconductor-electrolyte interface induces measurable shifts in threshold voltage, which scale with concentration in the nanomolar to micromolar range. The response is interpreted using a Langmuir-Freundlich adsorption model, indicating heterogeneous adsorption sites at the ZnO-Ag surface. These results demonstrate that ZnO-Ag WGFET devices provide a low-voltage and solution-processable platform for electrical detection of dye pollutants in water.

The escalating generation of electronic waste underscores the critical need for sustainable alternatives to conventional electronic technologies. Printed electronics emerge as a promising approach to address this issue by incorporating sustainable materials, implementing energy-efficient fabrication methods compatible with large-area manufacturing, and integrating end-of-life (EoL) strategies to minimize the environmental impact associated with waste management. In this work, we demonstrate fully printed Schottky diodes on kraft paper substrates fabricated using zinc (Zn) as a sustainable ohmic contact, zinc oxide (ZnO) nanoparticles as the semiconductor layer, and carbon nanotubes (CNTs) as the Schottky contact. The devices were manufactured using large area deposition processes at low-temperature and with vacuum-free printing techniques. The Cheung, Norde, and Mikhelashvili methods enabled the estimation of an effective Schottky barrier height of 0.75 ± 0.04 eV, a series resistance of 2.2 ± 1.5 kΩ, and a high ideality factor of 8.0 ± 1.4, which was corrected to 5.1 when it was voltage independent. These analyses also revealed the presence of trap states and the onset of a space-charge-limited current (SCLC) regime, with these electrical properties interpreted being considered and correlated with the morphological and structural characterizations. The diode exhibited a rectification ratio of (1.6 ± 1.2) × 103 and, in a proof-of-concept demonstration, successfully performed half-wave rectification, underscoring its potential for low-power and low-frequency sustainable electronic circuits on paper. Finally, life cycle assessments (LCA) showed the adopted manufacturing approaches and materials provide a lower impact route for fabricating sustainable diodes.

Implantable and wearable devices require antennas that are both miniaturized and efficient, yet conventional designs are constrained by narrow bandwidth and orientation sensitivity. We report overtone ultrawideband magnetoelectric (OUWB-ME) antennas that exploit higher-order acoustic modes in polished silicon substrates to achieve a 22.6-gigahertz -10-decibel bandwidth and overtone capability in the 3- to 4-gigahertz range. Packaged into "μBots," these magnetoelectric heterostructures bonded with silver nanoparticle inks maintain stable operation under biological loading. In vitro assays confirm the biocompatibility of aluminum nitride and the protective role of parylene encapsulation for iron-gallium. Ex vivo rat and human tissues reshape transmission and reflection spectra, with reproducible frequency windows near 3.3 and 3.9 gigahertz. μBots enable real-time audiovisual telemetry using software-defined radios and exhibit compatibility with 7-tesla magnetic resonance imaging. By combining wideband response, robustness to misalignment, and biocompatible packaging, OUWB-ME μBots provide a scalable platform for wireless bio-integrated communication and telemetry.

Herbicides and pesticides are widely used in agriculture, yet many of the substances used are harmful to human health or the environment. Sensing technology can be used to monitor contamination of water bodies or soil. However, traditional electronics systems are too bulky and expensive to be deployed for large area sensing. Moreover, with only similar to 20% of electronics waste recycled, there is a danger that use of sensors can contribute to another environmental problem. To overcome this, we have developed printed, compostable sensors, which are sensitive to different common agricultural pollutants. By combining impedance sensors with different sensitive layers, it is possible to not only determine the concentration of pollutant but potentially differentiate between different compounds using advanced data analytical techniques such as principal component analysis. The low environmental footprint makes this a promising approach toward large area agricultural monitoring.

The adoption of ‘Design-for-Recycling’ (DfR) approaches for manufacturing Electrical and Electronic Equipment is still in its infancy. However, growing interest in DfR is driven by its potential to address the global challenge of waste from electrical and electronic equipment (WEEE) and reduce the environmental footprint of electronics. In this study, a DfR approach that enables up to 99% material recovery using scalable laboratory methods is presented. Through Life Cycle Assessment (LCA), a 90% reduction in environmental impact compared to conventional Flame-Retardant Level 4 (FR4)-based printed circuit board assemblies manufacturing is demonstrated. To achieve this, a fully additive process is adopted with Heterogeneous integration using Ultra-Precise Deposition (UPD) to provide a more compact form factor with lower material use than conventional approaches. For recycling trials, selective recovery using Iron Chloride (FeCl₃) was adopted, enabling silver (Ag) to be recovered by mechanical filtration. The LCA results indicate a notable reduction in environmental impact and human toxicity, primarily due to the lower substrate footprint, reduced reagent use, the ease of disassembly and resource retention enabled by the DfR design. The results show that the integration of DfR principles with recycling establishes a new standard for electronics manufacturing, where technological performance and environmental accountability are simultaneously pursued.

Presented here is a biodegradable, bioinspired synaptic phototransistor (SPT) based on an electrolyte‐gated field‐effect transistor (EGFET) architecture for sustainable artificial intelligence vision systems (AIVSs). The EGFET is designed to be zero waste and degrades to benign end products at the end‐of‐life. The device is fabricated onto a poly(butylene adipate‐co‐terephthalate)/poly(lactic acid) (PBAT/PLA) bioderived substrate, which uses reduced graphene oxide (rGO) electrodes, a ZnO active layer, and honey as a natural gate electrolyte, enabling simultaneous sensing and memory of UV light stimuli. Through charge trapping/detrapping and field‐effect modulation, the device exhibits key neuromorphic behaviors including short‐ and long‐term plasticity, spike‐time‐dependent plasticity (STDP), and light‐response plasticity at low operating voltages and energy consumption. The EGFET demonstrates tunable memory via scan rate and sweep range modulation and maintains stable synaptic responses under varying UV intensities and exposure durations. A learning model simulating UV‐induced skin and ocular damage is proposed, highlighting the device's potential for wearables and health‐monitoring applications. Overall, the work demonstrates the feasibility of manufacturing SPT devices based on EGFETS using eco‐friendly materials for neuromorphic electronics while minimizing the growing e‐waste problem in electronics.

Efficient recycling of aged crystalline silicon photovoltaic (PV) modules is crucial due to rapidly increasing PV installations and associated waste streams. Current methods-mechanical, thermal, and chemical-often compromise material purity and environmental integrity. This paper introduces a novel approach employing near-infrared (NIR) pulsed laser (1060-1085 nm) to selectively ablate the ethylene-vinyl acetate (EVA) encapsulant from aged silicon PV modules. Results demonstrate a critical threshold for significant EVA removal at laser powers between 9-12 W, with a saturation effect above ~18 W (~45% mass loss). FTIR and XRD analyses confirm effective EVA removal and preservation of crystalline silicon integrity, respectively. This method establishes a precise, low-impact alternative significantly advancing circular economy strategies in photovoltaics.

This work addresses the limitations of traditional bondwires in millimeter-wave (mmWave) chip-to-PCB interconnections, particularly at high frequencies such as those in the E-band. The inherent inductance of bondwires significantly impairs impedance matching and contributes to elevated insertion loss as frequency increases. For instance, a single bondwire with a length of 480 mu m exhibits poor performance, with a return loss (S11) of -2 dB and an insertion loss (S21) of -4.6 dB at 73 GHz. While using multiple bondwires can offer marginal improvement, the performance remains suboptimal for high-frequency applications. To overcome these limitations, we propose the use of XTPL's Ultra-Precise Dispensing (UPD) technology for forming 3D-printed interconnects. These printed microstructures demonstrate significantly improved RF performance. At 73 GHz, a dual printed bond achieves an insertion loss better than 1 dB and a return loss better than 10 dB, highlighting its potential as a superior alternative to traditional wire bonding in mmWave system integration.

There is a pressing need to reduce electronic waste, which along with government edicts and national time‐bound policy directives are shaping the drive toward circular economy solutions in electronics. However, there is no industrially standardized approach for fabricating high‐throughput recyclable and reusable electronic assemblies. Herein, we present the functionalization of steel over large areas with low‐cost insulative intermediate layers as Printed Circuit Boards (PCBs), enabling an electronics circular economy. Roll‐to‐roll‐friendly reusable steel substrates are coated using Sol–gel‐based low‐roughness insulative layers, with conductive tracks and solder pads additively manufactured with direct‐write printing. To demonstrate how degradable 3D scaffolds could enable wireless applications, RF components, and wi‐fi nodes are demonstrated with 3D‐printed antennas showing the feasibility of broadband Internet of Things applications up to 6 GHz. At their end‐of‐life, the steel‐based PCBs are sonicated in non‐hazardous solvents allowing for the rapid recovery of components and precious metals. The environmental benefits of our approach are discussed using Life Cycle Assessments (LCA) and a comparative LCA between these scenarios has been undertaken. Consideration of the final product cost is given and potential business models to enter the electronics market are identified.

Recyclable, degradable and printed electronics are gaining attention as solutions to the growing e-waste problem, but achieving high-resolution, high conductivity circuits with low end-of-life waste footprint remains difficult. Here we show the demonstration of a Printed Circuit Board Assemblies where over 99

As deployment of photovoltaic (PV) systems intensify amidst the shift towards renewable energy sources, the imperative to minimise their environmental footprint across the full life cycle has become increasingly critical. Here, we introduce a novel Hybrid process for recovering silver (Ag) from monocrystalline silicon (Si) PV cells that achieves a 93 % Ag recovery yield. By selectively removing aluminium (Al) with sodium hydroxide (NaOH) and delaminating busbars using iron chloride (FeCl3), pure Ag is recovered by mechanical filtration, minimising purification needs. Life Cycle Assessment (LCA) indicated reduced climate change and human toxicity burdens compared to Conventional or Brine-based leaching, attributed to lower reagent consumption and fewer purification steps. Techno-economic analysis (TEA) highlighted cost challenges, indicating net losses due to high waste disposal fees and chemical usage, despite substantial revenue from recovered Ag. These findings highlight the critical role of high-value recycling and supportive policies in advancing a sustainable PV industry.

Sustainable food production is one of the key challenges that humanity must overcome to combat global malnutrition and meet the projected increase in the demand for food. Digital agriculture, with the application of sensors to monitor factors such as pH, humidity, and temperature, can improve the efficiency of crop production. However, the sustainability of these devices must be considered. In this work, we report the development of impedance-based pH sensors by using biodegradable materials. It is demonstrated that impedance is an effective way to measure differences in pH using a molybdenum disulfide-based sensor. These sensors can detect agriculturally relevant compounds, as demonstrated by ethephon in this paper, where the active compound's concentration alters the solution's pH. We also demonstrate how the molybdenum disulfide pH sensors can be used with our developed wireless sensor network, which can be used for field measurements, giving good agreement compared to impedance measurements using an electrochemical workstation. Life cycle assessment analysis shows that combining a recyclable wireless sensor network with replaceable and degradable sensors leads to a small environmental footprint. As such, this is a promising approach to digital agriculture, which can contribute to more sustainable food production while minimizing the level of electronic waste generation.

Many of the issues associated with recycling devices containing small but significant amounts of technology critical metals, arise from the choice of materials and, most importantly, the joining methods for different materials. In many cases, recycling could be simplified and made more efficient by employing design for recycle principles which consider the requirements for separation. This study highlights recent innovative recycling tools which can impart greater selectivity during material separation and shows how often small changes in device architecture can greatly simplify critical metal recovery and promote circularity. It also discusses how design can be used to enable these tools to be assembled into the recycling flowsheet, to decrease energy and chemical input and maximise the recovery of technology critical metals. It also promotes how digital product passports could be used in combination with AI to develop algorithms to develop smart recycling flowsheets.

The recent advances in optic neuromorphic devices have led to a subsequent rise in the development of energy-efficient artificial-vision systems. While the energy consumption of such devices is known to be much lower than conventional vision systems, it is known that manufacturing accounts for the largest share of the climate impact in microelectronics, dominating over the product use phase. Thus, there is a need to develop sustainable manufacturing processes and to adopt low-impact materials for hardware solutions of the future. In this study, an Electrolyte-Gated Organic Field-effect Transistor (EGOFET) is experimentally demonstrated for the implementation of a high-performing synaptic optical sensor using sustainable materials that degrade to benign products at the End of Life (EoL). The device shows remarkable light response with maximum Paired-Pulse Facilitation (PPF) Index of up to 151% at a light power density of 38 mu W cm-2, which enables artificial synaptic applications with an average power consumption as low as 2.4 pJ for each training process, representing one of the best among the reported results. To demonstrate the tunability of the vision system, an ensemble decision tree is used to enable the EGOFET to distinguish and remember different primary colors at different power densities with 95.6% accuracy.

Electronics based on natural or degradable materials are a key requirement for next-generation devices, where sustainability, biodegradability, and resource efficiency are essential. In this context, optimizing the molecular chemical structure of organic semiconductor compounds (OSCs) used as active layers is crucial for enhancing the efficiency of these devices, making them competitive with conventional electronics. In this work, honey-gated organic field-effect transistors (HGOFETs) were fabricated using four different perylene derivative films as OSCs, and the impact of the chemical structure of these perylene derivatives on the performance of HGOFETs was investigated. HGOFETs were fabricated using naturally occurring or low-impact materials in an effort to produce sustainable systems that degrade into benign end products at the end of their life. It is shown that the second chain of four carbons at the imide position present in perylenes N,N '-bis(5-nonyl)-perylene-3,4,9,10-bis(dicarboximide) (PDI) and N,N '-bis(5-nonyl)-1-naphthoxyperylene-3,4,9,10-bis(dicarboximide) (PDI-ONaph) reduces pi-stacking interaction in the active layer, leading to lower AC conductivity and the non-functionality of HGOFETs. On the other side, the chain-on molecular orientation in the film of N,N '-dibutylperylen-3,4:9,10-bis(dicarboximide) (BuPTCD) was fundamental for the efficiency of HGOFETs, showing a better performance than the HGOFETs of N,N '-bis(2-phenylethyl)-3,4:9,10-bis(dicarboximide) (PhPTCD), which has a face-on molecular orientation. Finally, the HGOFETs of BuPTCD and PhPTCD are good candidates as UV light detectors and are used for the detection of UV radiation.

Indium-gallium-zinc-oxide thin-film transistors (IGZO TFTs) are widely used in numerous display applications and are emerging as a promising alternative for flexible IC production due to their high transparency, superior field-effect mobility, and low-temperature processability. However, their stability under different voltage stresses remains a concern, primarily due to carrier trapping in the gate dielectric and point defect creation. This study involves the fabrication of IGZO TFTs and their subsequent bias stress testing in linear and saturation regions. The impact of a passivation layer on top of the active channel is investigated to mitigate bias stress susceptibility. The passivated TFTs exhibit reduced bias stress susceptance, with ΔVT only moderately affected by the positive gate bias stress. This suggests that fewer electrons are being trapped at the interface between the dielectric/semiconductor. Conventional bias stress testing methods for TFTs are time-consuming and depend on airstable devices. To address this, we introduce a ‘Voltage Step Stress’ (VSS) approach. This method offers an accelerated way to conduct bias stress measurements without compromising test accuracy.

Laser induced graphene (LIG), prepared directly with an in situ synthesis method onto Kraft Paper substrates, is proposed for the manufacture of biodegradable electronic devices. The investigation explores the influence of laser power and scanning speed on the properties of LIG conductive tracks and a sheet resistance of up to 0.25 k Omega sq-1. Raman spectroscopy and microscopy is used to analyse the interfacial properties, in particular the transition of cellulose fibers to carbonized graphene flakes through photothermal pyrolysis, leading to the formation of coral-like structures. To demonstrate the applicability of the approach, flexible resistive heaters have been manufactured and tests show rapid heating with a homogeneous distribution and a maximum temperature of 145.5 degrees C. Additionally, an electro-thermal conversion efficiency (hr+c) of 17.05 mW (degrees C cm2)-1 is achieved. Finally, a comparative Life Cycle Assessment with FR-4 based electronics has been undertaken and the environmental impacts are calculated. The impact assessment shows a two magnitude lower impact on the environment for most categories, which suggests the approach is beneficial for the environment at a global production level. The results show that the photothermal pyrolysis of Kraft paper using a laser diode allows for low-impact devices flexible and green electronics products. Laser Induced Graphene (LIG) is formed through Kraft paper pyrolysis, varying power and speed parameters. Achieving low sheet resistance and favorable morphology, the LIG proved suitable for conductive tracks in resistive heater applications. Results highlighted precise temperature control and rapid responses, demonstrating proof of concept with potential for real-world applications. Additionally, life cycle assessment demonstrated significantly reduced environmental impact. image

Current trends in manufacturing indicate that optimised decision making using new state-of-the-art machine learning (ML) technologies will be used. ML is a versatile technique that rapidly and accurately generates new insights from multifactorial data. The ML approach has been applied to a perovskite solar cell (PSC) database to elucidate trends in stability and forecast the stability of new configurations. A database consisting of 6038 entries of device characteristics, performance, and stability data was utilised, and a sequential minimal optimisation regression (SMOreg) model was employed to determine the most influential factors governing solar cell stability. When considering sub-sections of data, it was found that pin-device architectures provided the best model fittings with a training correlation efficiency of 0.963, compared to 0.699 for all device architectures. By establishing models for each PSC architecture, the analysis allows the identification of materials that can lead to improvements in stability. This paper also attempts to summarise some key challenges and trends in the current research methodologies. Current trends in manufacturing indicate that optimised decision making using new state-of-the-art machine learning (ML) technologies will be used.

This paper presents an innovative approach to sustainable circuit design through the development of recyclable printed circuit boards (PCBs). The proposed method involves the direct printing of circuits onto biodegradable substrates using a silver-based ink, followed by the integration of components via Ultra Precise Deposition (UPD) for fine wire interconnection of integrated circuits (ICs). This technique facilitates the assembly of a comprehensive Bipolar Junction Transistor (BJT) circuit. Notably, the circuit incorporates a touch sensor-fabricated using the same silver ink-that modulates the luminance of a surface-mount light-emitting diode (LED). This design not only prioritizes sustainability by ensuring the recyclability of the PCB substrates but also extends to the electronic components and the conductive silver tracks. The approach significantly advances sustainable practices in electronics manufacturing, enabling the complete recycling of all constituent components.