Magnesium Electrode Research Articles

Phosphate Removal Efficiency and Life Cycle Assessment of Different Anode Materials in Electrocoagulation Treatment of Wastewater

The excessive discharge of phosphorus-containing wastewater contributes to eutrophication, posing a serious threat to aquatic ecosystems. Therefore, methods such as electrocoagulation should be utilized to remove phosphorus from wastewater prior to discharging it into a water body. In this study, we aimed to determine the effectiveness of electrocoagulation in treating simulated phosphorus-containing wastewater under different parameters, including anode material (aluminum, iron, and magnesium), electrode distance (ED) (1, 2.5, and 4.5 cm), pH (3, 6, and 9), and current density (CD) (3, 6, and 9 mA/cm2). Additionally, three models of phosphate removal, the pseudo-first-order (PFO), pseudo-second-order (PSO), and Behnajady–Modirshahla–Ghanbery (BMG) models, were used to simulate the relationship between phosphate concentration and time in the electrocoagulation process using the three metals for phosphate removal. The experimental results showed that the aluminum system had the highest removal efficiency (90%) when energized for 20 min under a CD of 3 mA/cm2, followed by those of the iron (80%) and magnesium (35%) systems. Furthermore, a life cycle assessment (LCA) showed that the aluminum electrode system had a smaller environmental impact than the iron and magnesium electrode systems. Therefore, the aluminum electrode system is suitable for phosphorus removal from wastewater.

Producing p‐tolylmethanol derivatives through an eco‐friendly electro‐organic method: A highly efficient Grignard reaction utilizing a magnesium electrode

This research introduces an eco‐friendly and innovative technique for efficiently producing p‐tolylmethanol derivatives 4(a–k) using electro‐organic synthesis based on the Grignard reaction. By employing electrochemical methods, this approach offers several advantages, including enhanced reaction efficiency and reduced environmental impact. The process involves the electrochemical generation of the Grignard reagent, followed by its reaction with appropriate substrates to yield the desired p‐tolylmethanol derivatives. Our team optimized various reaction parameters like choice of solvent, electrode material, and reaction conditions to achieve high yields and selectivity. The developed electro‐organic method demonstrated outstanding efficiency and presents a fresh and environmentally conscious approach to synthesizing p‐tolylmethanol derivatives from benzaldehyde 1(a–e) and bromobenzene 2(a–h) via the Grignard reaction, yielding excellent results (85–93%). The resulting compounds were comprehensively characterized using melting point, 1H NMR spectroscopy, and CHN analysis to verify their structures. This electro‐organic approach holds significant potential as a sustainable strategy for synthesizing valuable organic compounds.

The Mg Electrode Cycling Mechanism in Simple Salt Glyme Electrolytes

The lithium-ion battery (LIB) has been at the forefront of innovations in energy storage since its commercialisation over 30 years ago. As we reach the practical specific capacity limit of current state-of-the-art materials, novel and innovative battery technologies are required to satiate the requirements of energy intensive applications such as electric vehicles. 1 The use of a lithium metal negative electrode has been proposed to increase the energy density, however the high reactivity causes poor cycling performance due to electrolyte degradation, dendrite formation and safety issues. 2 The magnesium electrode offers a solution that has double the theoretical volumetric capacity of the lithium electrode while simultaneously mitigating dendritic growth, reducing raw material costs and greatly increasing sustainability. 3,4 Previous work has shown that traditional LIB electrolytes are not compatible with magnesium metal, and the plating and stripping mechanism that underpins how magnesium electrodes cycle is poorly understood. 5 Here we explored the mechanism of magnesium plating and stripping in glyme-based electrolytes with a range of additional additives. We show that in the pure electrolyte solution, interphase formation is critical to stable cycling but that this is accompanied by significant degradation and accumulation of inactive Mg.6 We establish the three-dimensional chemical composition of Mg deposits in the different electrolyte formulations using a combination of focused ion beam-scanning electron microscopy (FIB-SEM), energy dispersive x-ray spectroscopy (EDX) and transmission electron microscopy (TEM). We use these findings to develop a mechanistic understanding that explains the electrochemical cycling performance of magnesium metal negative electrodes. In situ electrochemical quartz crystal microbalance (EQCM) measurements are used to evaluate the plating and stripping efficiency of the electrodes and to identify non-electrochemical degradation reactions between Mg and the electrolyte solutions.

Electrochemical Recovery of Phosphorus from Simulated and Real Wastewater: Effect of Investigational Conditions on the Process Efficiency

The development of recovery processes has become essential in recent years as a strategy to minimize environmental pollution while boosting circular economy and sustainable development. Due to the exponential growth in agricultural production and the increased pollution of waterbodies, the production of fertilizers from recovered phosphorus has become an alternative to phosphate rock-based production. In this work, the effect of different operational parameters in the efficiency of the electrochemical recovery of phosphorus, from organic and inorganic sources, was investigated. Among the studied variables, the most significant was the electrode material utilized in the system. The use of magnesium sacrificial electrodes, as AZ31 alloys, led to phosphorus removal from solution of above 90%, allowing the recovery of both orthophosphates and organic phosphorus (glyphosate) as struvite, brucite, and other amorphous compounds. Since there is a lack in the literature about the use of magnesium electrodes in real wastewater electrochemical treatment, system efficiency was also evaluated using a sanitary landfill leachate, reaching 96% of phosphorus recovery. The specific energy consumption and faradaic efficiency of the phosphorus recovery process were also assessed.

Evaluation of the electrical properties of carbon electrodes developed with bio-material additions as a sacrificial anode in cathodic protection

The use of zinc and magnesium sacrificial anodes for the protection of steel structures in cathodic protection techniques have been widely accepted but longevity and environmental friendliness of these materials in service still needs to be improved. Thus, the need to continually develop anodes that can potentially serve the same purpose and/or better performance. This work is a feasibility study on the production of carbon electrodes for possible application as sacrificial anodes for the cathodic protection of mild steel. The main aim of this investigation is to develop an electrode from carbon-based materials with a view to producing anodes that can potentially replace zinc and magnesium electrodes for cathodic protection of low-carbon steel. The electrodes were developed using mixture of coal, charcoal, mill scale, wood dust and coal tar (binder) that were heated and compressed in a metal die. The current passing through the electrodes was measured with the resistance, resistivity and conductivity determined, including the current densities (Iρ) which gives an indication of the electrochemical behavior of the electrodes. Morphology of the electrodes were examined by optical microscope (OM) and scanning electron microscope (SEM) to assess the influence of porosities of the electrodes produced. Based on these findings, it was generally observed that the conductivity increases from 5.23E-4 S/m to 5.87E-3 S/m for 150 µm and 600 µm particle sizes, respectively. Generally, resistivity increases with an increase in the amount of wood dust in the carbon anodes developed. The carbon electrode of 600 µm particle size with the composition of 67 wt% coal, 5 wt% charcoal, 10 wt% coal tar, 10 wt% mill scale and 8 wt% wood dust had the best current density that could offer corrosion protection for mild steel.

Selective Separation between Ammonium and Potassium in a Membrane-Separated Magnesium-Based Electrochemical Process

Increasing trends in global food and water demands alongside growing environmental concerns press the need for developing new wastewater management strategies. Modern wastewater treatment facilities should provide nutrient recovery and recycling, localized production capabilities, and low energy consumption. Magnesium-based electrochemical wastewater treatment processes are one technology option with the potential to address these needs by providing opportunities for simultaneous recovery of valuable resources from waste streams. In this system, phosphate and ammonium coprecipitate with the magnesium released from the sacrificial anode, producing struvite, NH4MgPO4, as a fertilizer. This technology also eliminates the disadvantages of the commonly used chemical precipitation method of struvite recovery, including magnesium salt dosing, and adding base to the system for pH control, due to in situ magnesium corrosion and hydroxide production at the magnesium anode surface.In this presentation, we specifically focus on a membrane-separated electrochemical process with a solid magnesium electrode. A complex synthetic water matrix including key ions such as ammonium, potassium, and phosphorus with other background salts was made for the anodic chamber to simulate animal liquid manures. Sodium sulfate solution was used as the supporting electrolyte on the cathodic chamber. Two different cation exchange membranes (CEMs) were placed between the two compartments to separate the anolyte from the catholyte. All experiments were conducted under OCV (no external energy input), and ion concentrations in each chamber were tracked over time using ion chromatography to perform kinetic study. The produced precipitates from each experiment are collected and have been characterized by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) to identify the morphology and purity of the produced solid precipitates. Furthermore, X-ray diffraction (XRD) and Fourier-transform infrared spectrometry (FT-IR) were used to exactly identify the nature of the precipitates. Experimental results indicate that magnesium electrode corrosion under OCV in the anolyte will decrease ammonium separation through the CEM to the catholyte compared to potassium.

Electro-galvanic alkalization and treatment of rainwater to obtain drinking water

ABSTRACT Rainwater Electro-Galvanic Alkalization (EGA) was performed using copper and magnesium (1:1) electrode. Efficiently removal of pollutants without external energy consumption was carried out, in addition essential ions were dosed for alkalization of rainwater. The optimal system conditions were obtained using response surface methodology (RSM) by considering the following operating variables: flow rate and concentration of the supporting electrolyte (NaCl and CaCl2). Furthermore, the maximum efficiency of nitrate, ammoniacal nitrogen, colour, and turbidity removal was evaluated. The results showed that the response variables were mainly sensitive to the type of supporting electrolyte used and the flow rate. Under experimental conditions of 0.009 M (NaCl) and 20 mL min−1, the removal rate was 74.19%, 72.49%, and 81.43% for nitrates, colour, and turbidity, respectively, and the lowest concentration of ammoniacal nitrogen ( 0.99 mg L − 1 ) was obtained. The kinetic models for nitrate and colour were fitted to zero-order models with k = 0.33 mg L − 1 mi n − 1 and k = 0.933 Pt − Co , respectively. In addition, turbidity was fitted to a first-order model ( k = 0.1661 mi n − 1 ) , and ammoniacal nitrogen was fitted to a second-order model ( k = 0.0217 L m g − 1 mi n − 1 ) . The concentration increases of minerals such as Ca and Mg, which rises the rainwater alkalinity after treatment (pH shift from 6.1 to 8.91), was determined by inductively coupled plasma (ICP) analysis.

Removal of Boron from Simulated Iraqi Surface Water by Electrocoagulation Method

The removal of boron from aqueous solution was carried out by electrocoagulation (EC) using magnesium electrodes as anode and stainless steel electrodes as cathode. Several operating parameters on the removal efficiency of boron were investigated, such as initial pH, current density, initial boron ion concentration, NaCl concentration, spacing between electrodes, electrode material, and presence of carbonate concentration. The optimum removal efficiency of 91. 5 % was achieved at a current density of 3 mA/cm² and pH = 7 using (Mg/St. St. ) electrodes, within 45 min of operating time. The concentration of NaCl was o. 1 g/l with a 0.5cm spacing between the electrodes. First and second order rate equation were applied to study adsorption kinetics. The adsorption process follows second order kinetic model with good correlation. The energy consumption was evaluated for the optimum operating conditions. It was in the range of 1.296 to 1.944 Kwh/m3 . The overall expected increase in the operating cost of water treatment using membrane desalination facility (for example) will be about 20%.

Methylamine Magnesium Borohydrides as Electrolytes for All-Solid-State Magnesium Batteries

Solid-state magnesium electrolytes may pave the way for novel types of rechargeable, sustainable, and cheap batteries with high volumetric and gravimetric capacities. There are, however, currently no solid-state magnesium electrolytes that fulfill the requirements for solid-state battery applications. Here, we present the synthesis, structure, and properties of six new methylamine magnesium borohydride compounds, α- and β-Mg(BH4)2·6CH3NH2, Mg(BH4)2·3CH3NH2, and α-, α′- and β-Mg(BH4)2·CH3NH2. The β-Mg(BH4)2·CH3NH2 polymorph displays a record high Mg2+ ionic conductivity of σ(Mg2+) = 1.50 × 10–4 S cm–1 at room temperature. The high Mg2+ conductivity of β-Mg(BH4)·CH3NH2 is facilitated by a one-dimensional chain-like structure interconnected by weak dihydrogen bonds and dispersion interactions, forming a migration pathway across the chains. The oxidative stability of Mg(BH4)2·CH3NH2 is ∼1.2 V vs Mg/Mg2+, and the reversible plating and stripping were confirmed by cyclic voltammetry and symmetric cell cycling, revealing high stability toward magnesium electrodes for at least 50 cycles at 60 °C.

Removal of ammonium and phosphate from slaughterhouse wastewater by electrochemical method using magnesium electrodes

In this research, the treatability of slaughterhouse wastewater was investigated by using the electrochemical method with Mg electrodes. The influence of the variables such as initial pH (4, 5, 6, 7, 8, and 9), current density (15, 30, and 45 mA/cm2), and reaction time (20, 25, and 30 min) on the removal efficiency of ammonium and phosphate was studied. The highest phosphate removal efficiency was reached at 100% after 20 min of electrochemical treatment with 30 mA/cm2 of current density and initial pH 6. Meanwhile, the maximum removal percent of ammonium was approximately 52%. Thus, this method is feasible to apply for the removal of phosphate and ammonium in slaughterhouse wastewater.

Surface Amalgam on Magnesium Electrode: Protective Coating or Not?

A better control of the metal–electrolyte interface is mandatory to help the development of rechargeable magnesium batteries. Protecting the magnesium surface by a coating layer to avoid its passivation with conventional liquid electrolytes is a promising strategy. Herein, in contact with a mercury droplet, a crystalline amalgam layer is created on the surface of magnesium. After the creation of this surface coating, a remarkable improvement of the plating/stripping process is observed with magnesium bis(trifluoromethanesulfonyl)imide/dimethoxyethane electrolyte, whereas strong surface passivation hindering electrochemical cycling occurs when using bare magnesium. The detailed investigation of the evolution of the amalgam layer during cycling, however, shows substantial chemical and morphological electrochemical changes, eventually showing that such a layer does not act as a protecting coating, but rather as an independent electrode material deposited on an inert Mg substrate.

Synergistic electrocoagulation–precipitation process using magnesium electrodes for denim wastewater treatment: Bifunctional support electrolyte effect

The textile industry is one of the most polluting activities since its processes handle >8000 different types of chemical products. It consumes a significant volume of water, for example, a denim dying process requires from 30 to 50 L/kg. The goal of this study was to determine the synergistic effect of the electrocoagulation–chemical precipitation treatment (EC–CP) on real textile wastewater from the denim industry. MgCl2, CaCl2, and MgSO4 were tested for CP, and CaCl2 exhibited the best results: 77, 76, and 77 % of COD, color, and turbidity were removed, respectively. EC batch treatment was performed with an anode of Mg and a cathode of Fe at a pH of 4.5, treatment time was 29 min, and current density 144.7 A/m2 (1.7 A). The optimal conditions were obtained by using a Box–Behnken model, with removal efficiencies of 93, 87, and 93 % for COD, color, and turbidity, respectively. The main contribution and conclusion of this work were the bifunctional effect of the electrolyte (CaCl2) improves the conductivity and precipitates the pollutants. The Mg anode removes efficiently the organic matter and the nutrients (N and P) by complexation, the synergistic EC–CP achieved removal efficiencies were 91, 93, and 94 % for COD, color, and turbidity, respectively. The energetic costs for EC and EC–CP treatments were 1.82 and 0.25 US$/m3, respectively.

Application of Pulsed Potential Waveform in Electrochemical Phosphate Recovery As Struvite from Wastewater

Phosphate production is apprehended to peak as early as 2030, and post-peak, phosphate production, and thus food supply, will be limited by dwindling resources, strained economics, and reduced rock quality, with remaining resources expected to last 50-300 years. The limited supply of phosphate demands P conservation by changing the food production system, from fertilization to wastewater treatment. Stuvite (MgNH4PO4.6H2O) has been recognized as a high-value, slow-release, effective fertilizer that can be obtained from both solid (e.g., food, animal, and human waste) and liquid wastes (e.g., wastewater from industrial, municipal, and agricultural operations). The goal of our research is to recover struvite from wastewater using an alkaline electrochemical reactor with a magnesium alloy anode and a cathode constructed of standard catalysts for reducing water to hydrogen gas and hydroxide. Over time with successive reactor batches, the magnesium electrode used to generate magnesium cations in solution and precipitate struvite becomes severely fouled, which in turn increases energy demand and decrease struvite fertilizer recovery. A dynamic, pulsed voltage waveform, as opposed to a constant voltage, causes a stress-strain-like effect at the magnesium electrode surface, thereby preventing or reducing the amount of struvite precipitate that would attach to the electrode. In an aqueous solution of ammonium dihydrogen phosphate (NH4H2PO4, 10 mM) at neutral pH, a significant 50% increase in magnesium release is observed compared to constant voltage applications, resulting in a 30% increase in phosphate recovery. Studies of the recovered precipitate using X-ray diffraction and scanning electron microscopy (SEM) indicate the presence of struvite.

Ultrasound-driven in vivo electrical stimulation based on biodegradable piezoelectric nanogenerators for enhancing and monitoring the nerve tissue repair

In vivo electrical stimulation (ES) has shown great promise in promoting tissue repair for various tissue engineering applications. However, a significant limitation of current long-term ES technique is that the existing postoperative protocols with transcutaneous leads have great risk of infection and need second operation to remove the tethered electrical-interface. Herein, we explored an ultrasound-driven in vivo ES technique based on the biodegradable piezoelectric nanogenerator (PENG) without any transcutaneous leads for the repair of peripheral nerve injuries. The piezoelectric nanogenerator contains biodegradable piezoelectric materials, including potassium sodium niobate (KNN) nanowires, poly (L-lactic acid) (PLLA), and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), biodegradable encapsulation layers, such as Poly (lactic acid) (PLA) or poly-ɛ-caprolactone (PCL) films, as well as biodegradable magnesium (Mg) electrodes and molybdenum (Mo) wires. Owing to the merits of ultrasound (US) in biomedical engineering, such as deep tissue penetration and predominant clinical security, US was selected as an exterior wireless energy source to drive the implantable nanogenerators which were fabricated with dissolvable piezoelectric films. With mechanical excitation remotely activated by programmable US pulses, the implanted piezoelectric nanogenerator can deliver adjustable ES to the biodegradable conductive conduits of peripheral nerves beyond the intraoperative period. Moreover, upon in-situ ES of the recovered nerves by the implanted nanogenerator, the nerve repairing process can be monitored in real-time with recorded muscle electrophysiology response. With a sciatic nerve injury model, our comprehensive investigation on neurologic function recovery analysis, histological assessment and microstructure analysis confirmed the great enhancement in nerve regeneration by the ultrasound-driven in vivo ES. This work provides a novel strategy with ultrasound-responsive biodegradable piezoelectric nanogenerator to deliver in vivo ES for tissue engineering applications.

Production of struvite by magnesium anode constant voltage electrolytic crystallisation from anaerobically digested chicken manure slurry

Nitrogen and phosphorus levels in livestock manure and digestive fluid are high, posing a threat to soil and water quality and necessitating nutrient removal and recovery. Phosphorus recovery has the potential to alleviate the global phosphorus resource crisis. This study proposed a magnesium anode constant voltage electrolysis method to crystallise struvite (magnesium ammonium phosphate hexahydrate, MgNH4PO4·6H2O) from anaerobically digested chicken manure slurry using reaction kinetics at variable constant voltages ranging from 2 V to 12 V. The recovery of nitrogen and phosphorus was shown to be effective over a wide initial pH range (3.00 ± 0.03–7.90 ± 0.10) using synthetic digestion fluids. Moreover, the pH gradually increased during the reaction without any external chemical adjustments. The phosphorus recovery rates conformed to the first-order kinetic model, with a maximum rate constant of 2.13 h−1. When the best voltage of 2 V was used at 25 ± 1 °C, the recovery rate reached 5.24 mg P h−1cm−2 in the synthetic digestion fluids during 90 min and 4.60 mg P h−1cm−2 in the anaerobically digested chicken manure slurry. The crystalline products recovered were identified as high-purity struvite by XRD and XPS. The purity of recovered struvite with an initial pH of 3.00 and 7.90 was 96.5% and 98.9%, respectively. These results demonstrated that the magnesium electrode could rapidly react with nitrogen and phosphorus to generate high-purity struvite.

INVESTIGATING THE ELECTROLYTE MEDIUM FOR ELECTRIC GENERATION USING PROBIOTIC YOGURTS

Rationale: The importance of energy generation cannot be emphasized enough in every aspect. Even though the traditional electrical generation has been mainly focused on high voltage sources such as hydroelectric and nuclear power, the low-power sources of electrical acquisition are also essential, particularly in the era of digital technology. Batteries have been advanced as an integral component of electric devices for decades. The advent of digital technology leads us to the necessity of low-power energy sources. Electrolyte batteries consist of a pair of metal electrodes in an aqueous solution that facilitates electron transfer through the medium when a circuit is formed. New ideas for these low-power electrical generations have been tried around, even using potatoes, apples, and mud.
 Methods: This study investigated yogurt as the electrolyte medium using a metal pair of stainless steel and coiled magnesium electrode. A four-channel data acquisition system recorded the electric generation waveforms from the electrochemical battery cells changing the variables as examined, such as temperature, concentration, pH, stirring power, serial connection, and whole concentration. 
 Results: The study confirmed that the pair of coiled Mg and stainless-steel electrodes produced the highest electrical potential, 25% higher among the metal pairs tested, while Chobani brand yogurt was the best electrolyte, 10% higher for electricity generation. The variables of temperature, concentration, pH, and stirring power were all highly linearly related to electricity generation. Serial combination with the 4 battery cell study demonstrated the feasibility of high voltage generation up to 7.8V.
 Conclusions: The highest electrical potential was acquired when used the whole yogurt of Chobani with stainless steel and coiled-type electrodes. The study demonstrated the superiority of probiotic yogurt electrolytes, which might need to elaborate for further detailed mechanisms.

Towards Solid‐State Magnesium Batteries: Ligand‐Assisted Superionic Conductivity

AbstractSolid‐state inorganic magnesium batteries are considered as potential high energy storage devices of the future. Here we present a series of magnesium borohydride tetrahydrofuran (THF) composites, Mg(BH4)2 ⋅ xTHF(−MgO), 0≤x≤3, as solid‐state electrolytes for magnesium batteries. Three new monoclinic compounds were identified, Mg(BH4)2 ⋅ 2/3THF (Cc), α‐Mg(BH4)2 ⋅ 2THF (P21/c) and β‐Mg(BH4)2 ⋅ 2THF (C2), and the detailed structures of α‐ and β‐Mg(BH4)2 ⋅ 2THF are presented. The magnesium ionic conductivity of composites formed by these compounds were several orders of magnitude higher than that of the distinct compounds, x=0, 2/3, 2, and 3. The nanocomposite stabilized by MgO nanoparticles (∼50 nm), Mg(BH4)2 ⋅ 1.5THF−MgO(75 wt%), displayed the highest Mg2+ conductivity, σ(Mg2+)∼10−4 S cm−1 at 70 °C, a high ionic transport number of tion=0.99, and cyclic voltammetry revealed an oxidative stability of ∼1.2 V vs. Mg/Mg2+. The electrolyte was stable towards magnesium electrodes, which allowed for stable Mg plating/stripping for at least 100 cycles at 55 °C with a current density of 0.1 mA cm−2. Finally, a proof‐of‐concept rechargeable solid‐state magnesium battery was assembled with a magnesium metal anode and a TiS2 cathode. A maximum discharge capacity of 94.2 mAh g−1 was displayed, which corresponds to y=0.2 in MgyTiS2.

Implantation of an Impedance Sensor for Early Detection of Gastrointestinal Anastomotic Leaks

IntroductionAccurate early diagnosis of a gastrointestinal anastomotic leak remains a challenge. When an anastomotic leak develops, the electrical properties of the tissue undergoing inflammatory processes change, resulting from the extravasation of inflammatory fluid and cellular infiltration. The method described here intends to provide a novel early anastomotic leak warning system based upon measurable changes in tissue impedance nearby an acute inflammatory process. MethodsA biodegradable Mg-alloy was compared with a nonabsorbable stainless steel (STS) electrode connected to a wireless recording system for impedance measurement. In vitro measurements were made in physiological solutions and small animal (eight mice) and large animal (eight pigs) models with an anastomotic leak simulated by an open colotomy. Measurements were made at 10 mm intervals from the open colon at baseline and up to 120 min comparing these with a sutured colonic wound and normal tissue. ResultsIn-vitro biodegradable magnesium electrode impedance evaluation showed good sensitivity to different media due to its environmental corrosion properties. The impedance of an acidic environment (1.06 ± 0.02 kΩ for citric acid) was twice that of phosphate-buffered saline (PBS) (0.64 ± 0.008 kΩ) with a distinction between Normal Saline (0.42 ± 0.013 kΩ) and PBS (0.64 ± 0.008 kΩ). This was in contrast to the performance characteristics of the control STS electrodes, where impedance in an acidic environment was lower than saline or PBS (citric acid:0.76 ± 0.01 kΩ versus PBS: 1.32 ± 0.014 kΩ). In a mouse model simulating an anastomotic leak, there was a significant increase in impedance after 120 min when compared with controls (99.7% increase versus 9.6% increase, respectively; P < 0.02). This effect was confirmed in a pig model when relative impedance measurements of the leak and control groups were compared (1.86 ± 0.46 versus 1.07 ± 0.02, respectively; P < 0.027). ConclusionsElectrophysiological measurement shows diagnostic sensitivity for a gastrointestinal leak with potential clinical utility in the postoperative detection of early intra-abdominal sepsis. Further investigation of biodegradable tissue sensors capable of monitoring an early anastomotic leak is required.

Functional Encapsulating Structure for Wireless and Immediate Monitoring of the Fluid Penetration

AbstractWith the fast‐paced development of biomedical electronics, monitoring physiological processes have become ubiquitous throughout the field of implantable devices. Nevertheless, inherent challenges remain extant when long‐term applications are concerned. For the stable and reliable function of these devices, hermetic and biocompatible encapsulation is of paramount importance; however, extrinsic defects and intrinsic swelling properties of the encapsulating layer present the key limitation to ideal barrier performance. Thus, the ability to monitor biofluid penetration and predict the device's functional lifespan is necessary for safe and stable operation within the body. This paper presents the functional encapsulation structure that quantitatively measures the diffusion of fluids into the encapsulation layer. The hydrolysis of Magnesium (Mg) electrodes underneath the encapsulating material shows the capability to wirelessly monitor the water penetration rate and the presence of defects, such as pinholes and cracks, in the encapsulating material. The experiments conducted throughout this paper analyze the Mg thickness and geometry of the antenna to optimize the device's susceptivity to water penetration when submerged in aqueous environments. The facile fabrication process and the compatibility with prevailing implantable electronics further substantiate the device's usability in diverse applications where chronic implants are necessary for monitoring disease or administering required treatments.

Alloying electrode coatings towards better magnesium batteries

The surface of magnesium electrodes are protected through the action of liquid gallium. The resulting alloy coating enables enhanced plating/stripping and consequently better magnesium full cells with conventional electrolytes.