Search Results (448)

Acoustic coupling agents serve as critical interfacial materials connecting piezoelectric transducers with microfluidic chips in acoustofluidic systems. Their performance directly impacts acoustic wave transmission efficiency, device reusability, and reliability in biomedical applications. Considering the rapidly growing body of research in the field of acoustic microfluidics, this review aims to serve as an all-in-one reference on the role of acoustic coupling agents and relevant considerations pertinent to acoustofluidic devices for anyone working in or seeking to enter the field of disposable acoustofluidic devices. To this end, this review seeks to summarize and categorize key aspects of acoustic couplants in the implementation of acoustofluidic devices by examining their underlying physical mechanisms, material classifications, and core applications of coupling agents in acoustofluidics. Gel-based coupling agents are particularly favored for their long-term stability, high coupling efficiency, and ease of preparation, making them integral to acoustic flow control applications. In practice, coupling agents facilitate microparticle trapping, droplet manipulation, and biosample sorting through acoustic impedance matching and wave mode conversion (e.g., Rayleigh-to-Lamb waves). Their thickness and acoustic properties (sound velocity, attenuation coefficient) further modulate sound field distribution to optimize acoustic radiation forces and thermal effects. However, challenges remain regarding stability (evaporation, thermal degradation) and chip compatibility. Further aspects of research into gel-based agents requiring attention include multilayer coupled designs, dynamic thickness control, and enhancing biocompatibility to advance acoustofluidic technologies in point-of-care diagnostics and high-throughput analysis. Full article

Mobile phone waste management is a growing environmental challenge, with improper disposal contributing to resource depletion, pollution and missed opportunities for material recovery. This study presents the findings of a dual-purpose survey (11,163 respondents) conducted in a wide academic context in Italy, aimed at both assessing mobile phones disposal behaviors and knowledge and raising awareness through structured educational prompts about sustainable e-waste management. The results reveal significant behavioral patterns and knowledge gaps across demographic groups. While most respondents (90.6%) own one phone, males tend to have more than females. Phones are replaced every 3–5 years by 48.8% of users and every 1–3 years by 36.7%, with students tending to replace them earlier. Only 20.2% replace their phone when irreparable while 46% replace them due to high repair costs. A large majority (92.3%) store old devices at home, forming an estimated urban mine of 29,799 unused phones. The awareness of hazardous components is higher than that of critical raw materials, with males more informed than females and students in scientific fields displaying greater awareness than those in humanities and health disciplines. The awareness of official take-back programs is particularly low, especially among younger generations. Notably, 90% reported increased awareness from the educational survey and 93.1% expressed willingness to use an on-campus e-waste collection system. These results highlight the role of universities as catalysts for sustainable behavior, supporting the design of targeted educational strategies and policy actions in line with circular economy principles and Sustainable Development Goal 12 “Responsible consumption and production”. Full article

An electrochemical aptasensor was developed for the rapid and sensitive detection of ciprofloxacin (CPX) in milk samples. The device was fabricated on a polyethylene terephthalate (PET) substrate using a screen-printing technique with carbon-based conductive ink. Gold nanoparticles (AuNPs) were incorporated to enhance aptamer immobilization and facilitate electron transfer at the electrode surface. The sensor’s analytical performance was optimized by adjusting key parameters, including AuNP volume, DNA aptamer concentration, and incubation times for both the aptamer and the blocking agent (6-mercapto-1-hexanol, MCH). Differential pulse voltammetry (DPV) measurements demonstrated a linear response ranging from 10 to 50 nmol L⁻¹ and a low detection limit of 3.0 nmol L⁻¹. When applied to real milk samples, the method achieved high recovery rates (101.4–106.7%) with a relative standard deviation below 3.1%, confirming its robustness. This disposable and cost-effective aptasensor represents a promising tool for food safety monitoring, with potential for adaptation to detect other pharmaceutical residues in dairy products. Full article

The increasing volume of global waste presents a critical environmental and societal challenge, demanding innovative solutions to support sustainable practices such as recycling. Advances in Computer Vision (CV) have enabled automated waste recognition systems that guide users in correctly sorting their waste, with state-of-the-art architectures achieving high accuracy. More recently, attention has shifted toward lightweight and efficient models suitable for mobile and edge deployment. These systems process data from integrated camera sensors in Internet of Things (IoT) devices, operating in real time to classify waste at the point of disposal, whether embedded in smart bins, mobile applications, or assistive tools for household use. In this work, we extend our previous research by improving both dataset diversity and model efficiency. We introduce an expanded dataset that includes an organic waste class and more heterogeneous images, and evaluate a range of quantized CNN models to reduce inference time and resource usage. Additionally, we explore ensemble strategies using aggregation functions to boost classification performance, and validate selected models on real embedded hardware and under simulated lighting variations. Our results support the development of robust, real-time recycling assistants for resource-constrained devices. We also propose architectural deployment scenarios for smart containers, and cloud-assisted solutions. By improving waste sorting accuracy, these systems can help reduce landfill use, support citizen engagement through real-time feedback, increase material recovery, support data-informed environmental decision making, and ease operational challenges for recycling facilities caused by misclassified materials. Ultimately, this contributes to circular economy objectives and advances the broader field of environmental intelligence. Full article

The parameters of electromagnetic emissions from the antenna of a wearable radio communication module (parameterizing device functionality) were investigated at different positions near the body where an antenna is located. The specific absorption rate (SAR) coefficient was also investigated as a way of parameterizing the absorption of electromagnetic radiation in the user’s body adjacent to the antenna in various locations. The modeled exposure scenarios concerned a body-worn device with a 2.45 GHz ISM band antenna (used, e.g., for Wi-Fi 2G/Bluetooth applications). The antennas were modeled as follows: (1) located directly on the body (considered to be a model of a disposable, adhesive device) or (2) next to the body (considered to be a model of a classic, reusable, wearable electronic device located inside a plastic housing). Several body sections adjacent to the antenna were considered: head, arm, forearm, and chest (simplified and anatomical body models were used). The numerical models of the exposure scenarios were verified by relevant laboratory tests using physical models. It was found that the use of simplified models of the human body (numerical or physical) may be sufficient when analyzing antenna performance and SAR in a user’s body, such as in studies regarding microwave imaging and sensing, wireless implantable devices, wireless body-area networks or SAR estimation. Full article

The rapid development of wearable electronics requires multifunctional, transient electronic devices to reduce the ecological footprint and ensure data security. Unfortunately, existing transient electronic materials need to be degraded in chemical solvents or body fluids. Here, we report green luminescent, water-soluble, and biocompatible piezoelectric nanofibers developed by electrospinning green carbon quantum dots (G-CQDs), mulberry silk fibroin (SF), and polyvinyl alcohol (PVA). The introduction of G-CQDs significantly enhances the piezoelectric output of silk fibroin-based fiber materials. Meanwhile, the silk fibroin-based hybrid fibers maintain the photoluminescent response of G-CQDs without sacrificing valuable biocompatibility. Notably, the piezoelectric output of a G-CQD/PVA/SF fiber-based nanogenerator is more than three times higher than that of a PVA/SF fiber-based nanogenerator. This is one of the highest levels of state-of-the-art piezoelectric devices based on biological organic materials. As a proof of concept, in the actual scenario of a rope skipping exercise, the G-CQD/PVA/SF fiber-based nanogenerator is further employed as a self-powered wearable sensor for real-time sensing of athletic motions. It demonstrates high portability, good flexibility, and stable piezoresponse for smart sports applications. This class of water-disposable, piezo/photoactive biological materials could be compelling building blocks for applications in a new generation of versatile, transient, wearable/implantable devices. Full article

The dynamic relationship between microplastics (MPs) in the air and on the Earth’s surface involves both natural and anthropogenic forces. MPs are transported from the ocean to the air by bubble scavenging and sea spray formation and are released from land sources by air movements and human activities. Up to 8.6 megatons of MPs per year have been estimated to be in air above the oceans. They are distributed by wind, water and fomites and returned to the Earth’s surface via rainfall and passive deposition, but can escape to the stratosphere, where they may exist for months. Anthropogenic sprays, such as paints, agrochemicals, personal care and cosmetic products, and domestic and industrial procedures (e.g., air conditioning, vacuuming and washing, waste disposal, manufacture of plastic-containing objects) add directly to the airborne MP load, which is higher in internal than external air. Atmospheric MPs are less researched than those on land and in water, but, in spite of the major problem of a lack of standard methods for determining MP levels, the clothing industry is commonly considered the main contributor to the external air pool, while furnishing fabrics, artificial ventilation devices and the presence and movement of human beings are the main source of indoor MPs. The majority of airborne plastic particles are fibers and fragments; air currents enable them to reach remote environments, potentially traveling thousands of kilometers through the air, before being deposited in various forms of precipitation (rain, snow or “dust”). The increasing preoccupation of the populace and greater attention being paid to industrial ecology may help to reduce the concentration and spread of MPs and nanoparticles (plastic particles of less than 100 nm) from domestic and industrial activities in the future. Full article

Over the last two decades, the use of photovoltaic panels for the production of electricity has increased significantly, which leads to the need to solve the problems concerning the decommissioning and disposal of the panels and the development of appropriate technologies for their recycling. One of the key steps in this process is the separation of the tempered glass layer. Various technologies and devices are known for separating the glass of the solar panel by cutting it with a knife, as well as other instruments, with the different methods being based on mechanical, chemical, and thermal processes and accordingly having their own advantages and disadvantages. This article proposes an innovative approach for the mechanical delamination of solar panels using a metal wire heated by Joule heating, with the potential to become an energy-efficient, economical, and environmentally friendly method. This publication presents results from experiments using this type of tool to separate the layers of solar panels. Photos from a thermal camera are presented, showing the heat distribution in the panel and the reached operating temperature of the heated metal wire, necessary to soften the EVA bonding layer. Full article

Unprocessed glass waste is commonly disposed of in landfills, posing a significant environmental threat worldwide due to its non-biodegradable nature and long decomposition period. The volume of this waste continues to increase annually, driven by increasing consumption of electronic and household devices, as well as the growing popularity and end-of-life disposal of solar panels and other glass products. Therefore, to promote the development of the circular economy and the principles of sustainability, it is necessary to address the problem of reusing this waste. This review article examines the chemical and physical properties of various types of glass waste, including window glass, bottles, solar panels, and glass recovered from discarded electronic and household appliances. It was determined that the most promising and applicable reuse, which does not require high energy consumption, could be in the manufacture of concrete, which is the most developed construction material worldwide. Glass waste can be incorporated into concrete in three different particle sizes according to their function: (a) cement-sized particles, used as a partial binder replacement; (b) sand-sized particles, replacing fine aggregate; and (c) coarse aggregate-sized particles, substituting natural coarse aggregate either partially or fully. The article analyses the impact of glass waste on the properties of concrete or binder, presents controversial results, and provides recommendations for future research. In addition, the advantages and challenges of incorporating glass waste in ceramics and asphalt concrete are highlighted. Full article

The BRCA-1 protein, recognized for its diagnostic relevance in a wide spectrum of malignancies, has been the focus of extensive investigation. In this study, an electrochemical immunosensor specifically designed for BRCA-1 detection was fabricated. The sensing platform utilizes disposable pencil graphite electrodes modified with a nanocomposite composed of gold nanoparticles (AuNPs), molybdenum disulfide (MoS₂), and chitosan (CS). This multifunctional nanostructure significantly promotes electron transfer efficiency and supports the effective immobilization of antibodies. The constructed immunosensor exhibited excellent analytical performance, with a linear detection range between 0.05 and 20 ng/mL for BRCA-1 and a notably low limit of detection at 0.04 ng/mL. The device maintained a relative standard deviation of 3.59% (n = 3), indicating strong reproducibility. In addition, a high recovery rate of 98 ± 3% was achieved in spiked serum samples, even in the presence of common electroactive interferents such as dopamine and ascorbic acid. These findings highlight the sensor’s promising applicability for the clinical detection of BRCA-1 and potentially other cancer-related biomarkers. Full article

Paper-based electronics have emerged as a sustainable, low-cost, and flexible alternative to traditional substrates for electronics, particularly for disposable and wearable applications. This review outlines recent developments in paper-based devices, focusing on sensors and paper-based field-effect transistors (PFETs). Key fabrication techniques such as laser-induced graphene, inkjet printing, and screen printing have enabled the creation of highly sensitive and selective devices on various paper substrates. Material innovations, especially the integration of graphene, carbon-based materials, conductive polymers, and other novel micro- and nano-enabled materials, have significantly enhanced device performance. This review discusses modern applications of paper-based electronics, with a particular emphasis on biosensors, electrochemical and physical sensors, and PFETs designed for flexibility, low power, and high sensitivity. Advances in PFET architectures have further enabled the development of logic gates and memory systems on paper, highlighting the potential for fully integrated circuits. Despite challenges in durability and performance consistency, the field is rapidly evolving, driven by the demand for green electronics and the need for decentralized, point-of-care diagnostic tools. This paper also identifies detection strategies used in paper-based sensors, reviews limitations in the current fabrication methods, and outlines opportunities for the scalable production of multifunctional paper-based systems. This review addresses a critical gap in the literature by linking device-level innovation with real-world sensor applications on paper substrates. Full article

We present a compact and cost-effective real-time PCR system designed for point-of-care testing (POCT), utilizing a PCB-based disposable chip and an open-platform CMOS camera. The system integrates precise thermal cycling with software-synchronized fluorescence detection and provides real-time analysis through a dedicated user interface. To minimize cost and complexity, a polycarbonate reaction chamber was integrated with a PCB-based heater and thermistor. A slanted LED illumination setup and an open-platform USB camera were employed for fluorescence imaging. Signal alignment was enhanced using device-specific region-of-interest (ROI) tracking based on copper pad corner detection. Thermal cycling performance achieved a heating rate of 8.0 °C/s and a cooling rate of −9.3 °C/s, with steady-state accuracy within ±0.1 °C. Fluorescence images exhibited high dynamic range without saturation, and the 3σ-based ROI correction method improved signal reliability. System performance was validated using Chlamydia trachomatis DNA standard (10³ copies), yielding consistent amplification curves with a Ct standard deviation below 0.3 cycles. These results demonstrate that the proposed system enables rapid, accurate, and reproducible nucleic acid detection, making it a strong candidate for field-deployable molecular diagnostics. Full article

Starch was plasticized with epoxidized soybean oil (ESO) modified by reaction with cinnamic acid (CA), and films were prepared using solvent casting from water/ethanol solutions. They exhibited good hydrophobicity, reduced water sensitivity, and showed the same transparency as glycerol-plasticized counterparts, but with less flexibility. Interestingly, modified ESO enhanced gelatinization and hindered retrogradation of the biopolymer. ESO was reacted with CA without the use of catalysts to obtain a β-hydroxyester; in order to optimize the synthesis process, different reaction conditions were explored, varying the stoichiometry and the heating cycles. Products were fully characterized by Fourier transform infrared (FTIR) spectroscopy, ¹H and ¹³C nuclear magnetic resonance (NMR), and the different reactions following the opening of the oxirane ring were discussed. The properties of the novel starch-based films prepared with modified ESO highlight their use in food packaging, disposable devices, and agricultural mulching films. Full article

Consumer-grade electronics are ubiquitous and can be used to manage a range of devices for various purposes. Such devices can be both mobile and stationary. They have become increasingly intelligent in operation, utilizing complex software. The circular economy is a trend in which everyday utility items are designed with recyclable and easily recyclable materials. The materials may not be durable, but they make it easy to dispose of them at the end of their life. In this paper, we extend the concept of the circular economy to the design of electronic devices using cardboard as a flat-pack surface material. We propose a small device design technique and discuss its associated issues, enabling novice users to construct, install, and calibrate custom-built electronic devices. This is in the form of a kit that includes a cardboard flat-pack, a flexible electronic circuit board, and an instruction manual. We also discuss a software design algorithm that can be used to calibrate the newly constructed device. We only consider stationary devices and investigate the proposed devices and software with a sedentary behavior monitoring application. A trial with human participants was conducted to determine the ease of contracting and initially installing the devices. The results show that the proposed approach is highly feasible for novice human users and a high degree of trust with such devices. Full article

Dealing with solid waste has always been a global concern, and construction waste is one of the most important parts. Addressing how to properly dispose of construction waste, reduce its negative environmental impact, and achieve effective resource recycling has emerged as an urgent problem to be solved. Technological innovation underpins efficient waste reduction, reuse, and recycling, but existing research often overlooks systematic and quantitative measurements of innovation initiatives. This study uncovers the development status and trends of construction waste recycling (CWR) technology, identifies key points and potential innovation directions for technological development, and also explores practical strategies to promote technological innovation and industrial growth. Through patent analysis, this study uncovers the current status of technological innovation within China’s CWR industry. A text mining approach is employed to analyze patent texts related to core technologies, explore topic contents, and identify topic intensities and evolution trends. A comparative analysis between China and the global dominant countries in CWR reveals China’s technological strengths and weaknesses. The results indicate that patent applications in China’s CWR industry are substantial, with a rapid growth rate, while its global competitiveness remains weak. The applicants are widely distributed, with traditional enterprises demonstrating strong innovation capabilities, while emerging and small-to-medium enterprises lack vitality. The industry has potential advantages in developing resource recycling devices and construction wastewater treatment technology, but the technological foundation in some other core technologies is weak. This study offers an overview of technological innovation initiatives in the CWR industry, representing a breakthrough in existing research. The findings will assist policymakers in formulating evidence-driven strategies to promote CWR. Full article