23 research outputs found
Advanced Flow Detection Cell for SPEs for Enhancing In Situ Water Monitoring of Trace Levels of Cadmium
No full textAn advanced anodic stripping voltammetry (ASV)-based Micro Electro Mechanical System (MEMS) sensor for cadmium (Cd) detection is presented in this study, which is cost-effective and efficient for in situ water monitoring, providing a crucial early warning mechanism, streamlining environmental monitoring, and facilitating timely intervention to safeguard public health and environmental safety. The rationale behind this work is to address the critical need for an in situ monitoring system for cadmium (Cd) in freshwater sources, particularly those adjacent to agricultural fields. Cd(II) is a highly toxic heavy metal that poses a significant threat to agricultural ecosystems and human health due to its rapid bioaccumulation in plants and subsequent entry into the food chain. The developed analytic device is composed of a commercial mercury salt-modified graphite screen-printed electrode (SPE) with a custom-designed innovative polydimethylsiloxane (PDMS) flow detection cell. The flow cell was prototyped using 3D printing and replica moulding, with its design and performance validated through COMSOL Multiphysics simulations to optimize inflow conditions and ensure maximum analyte dispersion on the working electrode surface. Chemical detection was performed using square wave voltammetry, demonstrating a linear response for Cd(II) concentrations of 0 to 20 μg/L. The system exhibited robust analytical performance, enabling 25–30 daily analyses with consistent sensitivity within the Limit of Detection (LoD) set by the law of 3 μg/L
Application of 3D and 4D Printing in Electronics
No full textNowadays, additive manufacturing technologies have impacted different engineering sectors. Three- and four-dimensional printing techniques are increasingly used in soft and flexible electronics thanks to the possibility of working contemporarily with several materials on various substrates. The materials portfolio is wide, as well as printing processes. Shape memory polymers, together with composites, have gained great success in the electronic field and are becoming increasingly popular for fabricating pH, temperature, humidity, and stress sensors that are integrated into wearable, stretchable, and flexible devices, as well as for the fabrication of communication devices, such as antennas. Here, we report an overview of the state of the art about the application of 4D printing technologies and smart materials in electronics
Exploring circularity in ceramic 3D printing: Possibilities and implementation
No full textNowadays, concepts such as recycling, reusing, and sustainability are gaining ground in a wide range of fields and sectors, including manufacturing. This paradigm shift from “produce-dispose” to “produce-reuse” is pushing manufacturers and producers to move from a linear economy to a circular one. This change in perspective seems more readily applicable to the world of additive manufacturing, as it offers the potential not only to reduce waste generation, but also to reintroduce discarded and recycled materials into the production chain. This implementation of a circular manufacturing approach could be applied to ceramic additive manufacturing. Is it a straightforward process to implement a circular solution into the production chain? Which are the implications for costs, energy requirements, emissions, and waste management? This open discussion aims to identify potential starting points and gaps for further evaluation of future application of circular economy concepts in the ceramic industry
3D-Printed MEMS in Italy
No full textMEMS devices are more and more commonly used as sensors, actuators, and microfluidic devices in different fields like electronics, opto-electronics, and biomedical engineering. Traditional fabrication technologies cannot meet the growing demand for device miniaturisation and fabrication time reduction, especially when customised devices are required. That is why additive manufacturing technologies are increasingly applied to MEMS. In this review, attention is focused on the Italian scenario in regard to 3D-printed MEMS, studying the techniques and materials used for their fabrication. To this aim, research has been conducted as follows: first, the commonly applied 3D-printing technologies for MEMS manufacturing have been illustrated, then some examples of 3D-printed MEMS have been reported. After that, the typical materials for these technologies have been presented, and finally, some examples of their application in MEMS fabrication have been described. In conclusion, the application of 3D-printing techniques, instead of traditional processes, is a growing trend in Italy, where some exciting and promising results have already been obtained, due to these new selected technologies and the new materials involved
Recyclability of ceramic powder in CerAM vat photopolymerization
No full textThe sustainability of the manufacturing industry is becoming an increasingly hot topic, particularly the reintroduction of waste into the production chain. The use of AM of ceramics can reduce waste and enable complex,
lightweight designs, however, practical routes to circularity remain underdeveloped. This investigation aims to
explore the potential of coupling these additive fabrication techniques with raw materials from alternative
sources of ceramics, such as printing wastes and error prints, developing a photocurable ceramic suspension for
DLP technology. For resin preparation, a polymeric premix was first prepared by combining a mixture of
different acrylate monomers as a photoreactive binder with a non-reactive plasticizing additive. Alumina was
recovered from failed green bodies following matrix burning out, parts grinding and sieving of the obtained
powder. Subsequent investigations of the powder by SEM imaging and EDX analysis were carried out to verify
particle morphology and average dimensions and to identify any contaminants in the recycled material. The
suspension viscosity and curing behaviour were measured. Finally, the mechanical characteristics of printed
parts, their density, their shrinkage, as well as possible contaminants, were evaluated, in order to understand the
impact of the recycling process on material performances and to determine its possible application fields. Tests
results provided a practical recycling potential for alumina in DLP, offering viable solutions in facilitating closedloop CerAM manufacturing
Advances in Water Resource Management: An In Situ Sensor Solution for Monitoring High Concentrations of Chromium in the Electroplating Industry
No full textConcerning environmental safety and mitigating the risk of water pollution, the electroplating industry, historically reliant on the use of elevated concentrations of heavy metals to achieve high-quality products, faces a crucial challenge in monitoring wastewater enriched with these metals, notorious for their adverse effects on ecosystems and human health. Chromium, in both oxidation states Cr (III) and Cr (VI), emerges as a prominently employed metal, yielding noteworthy outcomes throughout the galvanisation process. This research showcases the prototype of an automatic in situ sensor tailored to industry sustainability efforts to facilitate real-time monitoring and efficient water management. This custom sensor, characterized by sensitivity, reliability, and user-friendliness, utilizes UV-Vis colorimetric principle to detect Cr in both oxidation forms ranging from grams per litre (g/L) to parts per million (ppm). This is made possible by the unique vibrant colours induced by chromium ions, enabling the precise measurement of analyte concentrations. Thanks to 3D printing, this sensor system interacts with customized parts, designed and validated through simulation processes, for filtering out particulate that may interfere with the analysis. The outcome represents a synergistic blend of technology and environmental responsibility, aligning industrial processes with the goal of safeguarding water resources and ecosystems
Additive Manufacturing for Electronics (AME): Prototyping High Surface Area Substrates to Improve Thermal Performance
No full textNowadays, Additive Manufacturing for Electronics (AME) is gaining ground in device
fabrication for the numerous advantages of these types of manufacturing technologies,
such as fast production processes, freeform design, and low-cost prototyping. In this
scenario, the proposed research work is focused on evaluating an innovative strategy for a
common issue in power electronics, which is related to the generation of hotspots. To face
this problem, the 3D printing of ceramic substrates with different high surface areas was
studied to improve thermal dissipation. Together with improved thermal management, the
upper surface of the devices enabled the deposition of a desired conductive pattern and
the bonding of bare die components for device fabrication. Finally, thermal exchange was
monitored to verify the efficacy and efficiency of the devices’ dissipation capabilities. The
proposed models exhibited a 70% temperature reduction upon transitioning from air to
water. Furthermore, the operating temperature remained stable for 10 min, meeting the
specific requirements of the intended application
A one-way coupled hydrodynamic advection-diffusion model to simulate congested large wood transport
No full textAn advection-diffusion model is proposed to simulate large wood transport during high flows. The mathematical model is derived from the wood mass balance, taking into consideration both the wood mass concentration and the log orientation, which affects log transport and, most importantly, wood accumulation. Focusing on wood mass transport, the advection-diffusion equation is implemented in a hydrodynamic model to provide a one-way coupled solution of the flow and of the floating wood mass. The model is tested on a large series of flume experiments, involving at least 30 logs and different control parameters (flow Froude number, log length, diameter, release point). The validation through the experimental data shows that the proposed model can predict the correct displacement of the most probable position of the logs and to simulate with a sufficient accuracy the planar diffusion of the wooden mass. Transversal wood distribution is more accurate than the streamwise one, indicating that a higher control on the longitudinal diffusion needs to be implemented.Sanitary Engineerin
An Approach Towards a FEP-based Model for Risk Assessment for Hydraulic Fracturing Operations
No full textWe consider an exemplary scenario drafted in the context of the recently started EU-project FracRisk. The setting belongs to six scenarios representing diverse subsurface processes on different scales. A numerical approach considering sources, pathways and targets quantifies the environmental impact associated with this setting. A Global Sensitivity Analysis of properly defined output quantities takes into account uncertain parameters and operational conditions within a FEP-based evaluation of risk and counteractive measures. At this early stage of the project, this showcase of the general modeling workflow addresses migration of frac-fluid through a naturally fractured reservoir (source) to an overlying formation (target)
The Interaction of Calcium and Metabolic Oscillations in Pancreatic β-cells
No full textDiabetes is a disease characterized by an excessive level of glucose in the bloodstream, which may be a result of improper insulin secretion. Insulin is secreted in a bursting behavior of pancreatic β -cells in islets, which is affected by oscillations of cytosolic calcium concentration. We used the Dual Oscillator Model to explore the role of calcium in calcium oscillation independent and calcium oscillation dependent modes and the synchronization of metabolic oscillations in electrically coupled β -cells. We implemented a synchronization index in order to better measure the synchronization of the β -cells within an islet, and we studied heterogeneous modes of coupled β-cells. We saw that increasing calcium coupling or voltage coupling in heterogeneous cases increases synchronization; however, in certain cases increasing both voltage and calcium coupling causes desynchronization. To better represent an islet, we altered previous code to allow for a greater number of cells to be simulated.terdisciplinary Program in High Performance Computing (hpcreu.umbc.edu) in the Department of Mathematics and Statistics at the University of Maryland, Baltimore County (UMBC) in Summer 2016. This program is funded by the National Science Foundation (NSF), the National Security Agency (NSA), and the Department of Defense (DoD), with additional support from UMBC, the Department of Mathematics and Statistics, the Center for Interdisciplinary Research and Consulting (CIRC),
and the UMBC High Performance Computing Facility (HPCF). HPCF is supported by the U.S. National Science Foundation through the MRI program (grant nos. CNS-0821258 and CNS-1228778) and the SCREMS program (grant no. DMS-0821311), with additional substantial support from UMBC. Co-author Mary Aronne was supported, in part, by the UMBC National Security
Agency (NSA) Scholars Program through a contract with the NSA. Graduate assistant Janita Patwardan was supported by UMBC.https://ir.library.illinoisstate.edu/cgi/viewcontent.cgi?article=1013&context=spor
