Potentiometric textile-based pH sensor

Determining the pH of sweat provides valuable information for athletes and patient monitoring. This work presents a textile-based, highly sensitive pH sensor for pH determination. Three conductive fabrics (Argenmesh, Ristop silver and Sstainless steel mesh (SSM)) were modified with a pH sensitive electrodeposited iridium oxide film (EIROF). The three electrodeposited fabrics were characterized by impedance measurements. The stainless steel mesh showed the best sensitivity to pH changes and therefore was selected for further experiments. Two configurations of this fabric were evaluated, looking for improvement in pH sensitivity and temperature dependence. The best result was obtained with the configuration that maximizes the contact surface between the stainless steel fibers, showing an error of 0.15% in the pH measurement of a buffer solution. This configuration was also used to perform in vivo measurements, obtaining an error of 4% when compared to the measurements performed with a commercial pH test strip. The implementation of sensor into textiles brings some advantages such as comfort, biocompatibility and washability, among others; making the future incorporation of a sensor into a garment very possible.Fil: Zamora, Martín Lucas. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Domínguez, Juan Martín. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Trujillo, Ricardo Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; ArgentinaFil: Goy, Carla Belen. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Sanchez, Maria Alejandra. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Madrid, Rossana Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentin

DESIGN AND f-ABRIC AT! ON OF A SURFACE pH SENSOR FOR A REALTIME CORROSION MONITORING

The aim of this research is to design and fabricate a new pi I sensor that can be used to measure hydrogen ion activity on corroding metal surface in bulk solution or under deposit. Iridium oxide (lrOx) is used for proposed design as pH sensitive material. IrOx is a potentiometric sensor which its open circuit potential regarding a reference electrode is representative of pi I. The electrodcposition method of cyclic voltammetry approach is used for coating of IrOx on stainless steel substrate. The effects of scan rate. temperature. and number of cycles on the coating thickness of IrOx elcctrodeposited on a stainless steel substrate v.cre investigated in a statistical system. The central composite design. combined with response surface methodology, was used to study condition of electrodeposition

Super-Nernstian Potentiometric pH Sensor based on the Electrodeposition of Iridium Oxide Nanoparticles

This work reports an investigation into the synthesis and electrodeposition of iridium oxide nanoparticles to fabricate an Au-based super-Nernstian potentiometric pH sensor. Monodisperse ultrafine iridium oxide nanoparticles with a mean particle diameter of 1–2 nm were successfully synthesized by the facile alkaline hydrolysis method and electrodeposited on the surface of Au substrate using Cyclic Voltammetry (CV). Based on the result, it was observed that the iridium oxide deposited Au substrate had a rough surface morphology. It was also found that the as-prepared sensor exhibited an excellent pH sensitivity and good stability over a long period, with a super-Nernstian response value of -73.7 mV/pH

New Simple Modification of Dip, Spray and Cathodic Electrodeposition Coating Methods for Wire Coating (3D Coating)

In the current paper three most applied coating methods modified to suit wire coating (three dimensional coating). Capillary-gravitational coating (CGM) with natural motions considered to compensate the lifting of substrates, which normally occurs in the dip coating method. Besides a new economic-environmental friendly spray coating (EESM) assisted by the motor rotating to coat different wires, and branched cathodic electrodeposition (BCE) used also for the same mission. Thoroughly, several tests and evaluations carried out for those applied techniques. Remarkably, easy application detected for all modified methods. Unusually perfect morphology output and functional layers were synthesized. Comparison of all mentioned methods carried out considering loses and the number of coating time. Evaluation analysis has been comprehensively considered to find out capability of using these methods later on in the future

A 3U Cubesat Platform for Plant Growth Experiments

This thesis work presents the design, manufacturing, and ground testing of a 3U Cubesat platform intended for plant growth experiments. The structure is comprised of four identical, but independent plant growth chambers. Each of these accommodates about two cubic inches of soil, and the necessary air volume and moisture regulation to grow a fast-growing plant from seed to seed in 3-4 weeks. The plant growth is artificially stimulated by an array of light emitting diodes (LEDs) at grow light wavelengths that match the properties of chlorophyll, and is monitored by a suite of sensors: temperature, pressure, relative humidity, CO2, custom designed soil pH, soil moisture, and imaging. The latter takes periodic still pictures in the visible and infrared spectrum using LED based illumination at different wavelengths. These images are used to analyze the overall health of the plant and record the developmental stages of the plant growth. The platform is complemented with a raspberry Pi on board computer and a solar panel-based power generation system. The current scientific goal of this 3U Cubesat platform is to study the interactions of soil microbes (bacteria and fungus) and plants. The former can be a source of nutrients for plants and decrease induced stress on these in space conditions. The availability of four test chambers allow scientists to quantify changes and investigate emergent properties of the soil bacterial and fungal populations. The Cubesat design affords the opportunity to investigate the impact of physical factors such as pressure, temperature, microgravity, and space radiation on the soil bacteria and fungi, in addition to the overall plant health. While small scale biology experiments have been performed on Cubesats before, to our knowledge none of those involved plant growth stimulation and monitoring. This platform can be adapted and expanded to meet the requirements of similar scientific research

3D printable conductive materials for the fabrication of electrochemical sensors:A mini review

The review presents recent developments in the use of conductive materials that can be printed using additive manufacturing (3D printing), enabling the development of mass-produced electrochemical sensors of varying geometries. This review will highlight some key electroanalytical applications of 3D-printed electrochemical sensors and discuss their potential future capabilities. Keywords: 3D printing, Additive manufacturing, Electrochemistry, Conductive electrode, 3D printed electrode, Electrochemical senso

Development of a Novel Solid-State Sensor Electrode Based on Titanium Thin Film as an Indicator Electrode in Potentiometric and Conductometric Acid-Base Titration in Aqueous Solution

A modified Ti/(SnO2 + Sb2O3) electrode was prepared by thermal deposition on titanium substrate and its use as indicator electrode to potentiometric and conductometric acid-base titration in aqueous solution at 298 K was developed. The E-pH curve is linear with slope of 0.0512 V/dec at 298 K. The standard potential of this electrode, E0, was determined with respect to the SCE as reference electrode. The recovery percentages for potentiometric and conductometric acid-base titration for acetic acid against NaOH were calculated. The cell constant, specific conductance, and the molar conductance with dilution for some common electrolytes were measured

Research Progress in Electrodeposition Technology of Titanium-Based Iridium Oxide Electrode

钛基氧化铱电极作为DSA(dimension stable anode)中的典型电极,广泛应用于各个领域。目前工业生产的钛基氧化铱电极主要由传统热分解法制备,存在成本高昂,工艺繁琐,依赖人工劳动,无法大规模生产等问题,十分有必要探索开发新的制备技术。本文从沉积液配方、基底材料的选择及处理、电沉积方式以及沉积时间等方面系统地讨论了氧化铱电沉积制备技术的研究进展,包括作者课题组所作的一些工作及成果;分析了钛基氧化铱电极电沉积制备技术目前所面临的挑战,并给出一定建议;阐述了其应用前景,展望了其未来发展方向,希望更多的科研人员能投入到相关研究中。Titanium-based iridium oxide electrode has been widely used in various fields, such as electrocatalytic oxidation, biomedical applications, hydrometallurgical metal recovery, electro-osmotic dewatering, etc. At present, it is mainly prepared by traditional thermal decomposition method, however, which has high cost, cumbersome process, mainly relying on manual labor and cannot be mass-produced yet. It is, therefore, urgently necessary to explore new preparation technologies by focusing on electrodeposition technology, with technological characteristics such as eco-friendly and sustainable development. This article systematically discusses the research progress in iridium oxide electrodeposition preparation technology from the aspects of deposition solution formulation, base material selection and treatment, electrodeposition method and deposition time, etc. Some works and achievements, made by the author's research group, such as a new electrodeposition recipe of titanium-based iridium oxide electrode and the pretreatment of titanium with anodic oxidation for improving the stability of electrodeposited IrO2 electrode are also presented. The current challenges faced by the electrodeposition preparation technology of titanium-based iridium oxide electrode, including bad coating quality, weak bonding ability between coating and substrate, lack of the study on the theory about dynamic of electrodeposition and the problem of industrial applications are analyzed. Based upon the aforementioned challenges, some suggestions, for example, utilizing optimization of the electrodeposition, multi-deposition process combination, metal (such as tantalum, lanthanum) co-deposition, are given to solve for the problem of coating quality. The process of electrodeposition by utilizing in-situ electrochemical methods, and combined with COMSOL and other software to simulate the process, and then starting from both electrochemical theory and crystal growth theory, as well as the gradually perfect the theoretical research on electrodeposition of iridium oxide on titanium are summarized. Finally, the application prospects and future development directions are highlighted. It is expected that this brief review would offer critical insights and useful guidelines for developing superior electrodeposition technology of titanium-based iridium oxide electrode.通讯作者:吴旭E-mail:[email protected]:XuWuE-mail:[email protected]华中科技大学环境科学与工程学院,湖北 武汉 430074College of Environmental Science and Engineering, Huazhong University of Science and Technology ,Wuhan 430074, Hubei, Chin

Fabrication of a 3D Printed Porous Junction for Ag|AgCl|gel-KCl Reference Electrode

Fused filament fabrication (FFF) is a 3D printing method that is attracting increased interest in the development of miniaturized electrochemical sensor systems due to its versatility, low cost, reproducibility, and capability for rapid prototyping. A key component of miniaturized electrochemical systems is the reference electrode (RE). However, reports of the fabrication of a true 3D-printed RE that exhibits stability to variations in the sample matrix remain limited. In this work, we report the development and characterization of a 3D-printed Ag|AgCl|gel-KCl reference electrode (3D-RE). The RE was constructed using a Ag|AgCl wire and agar-KCl layer housed in a watertight 3D-printed acrylonitrile butadiene styrene (ABS) casing. The novel feature of our electrode is a 3D-printed porous junction that protects the gel electrolyte layer from chloride ion leakage and test sample contamination while maintaining electrical contact with the sample solution. By tuning the 3D printing filament extrusion ratio (k), the porosity of the junction was adjusted to balance the reference electrode potential stability and impedance. The resulting 3D-RE demonstrated a stable potential, with a potential drift of 4.55 ± 0.46 mV over a 12-h period of continuous immersion in 0.1 M KCl, and a low impedance of 0.50 ± 0.11 kΩ. The 3D-RE was also insensitive to variations in the sample matrix and maintained a stable potential for at least 30 days under proper storage in 3 M KCl. We demonstrate the application of this 3D-RE in cyclic voltammetry and in pH sensing coupled with electrodeposited iridium oxide on a gold electrode. Our method offers a viable strategy for 3D printing a customizable true reference electrode that can be readily fabricated on demand and integrated into 3D-printed miniaturized electrochemical sensor systems

Parylene Based Flexible Multifunctional Biomedical Probes And Their Applications

MEMS (Micro Electro Mechanical System) based flexible devices have been studied for decades, and they are rapidly being incorporated into modern society in various forms such as flexible electronics and wearable devices. Especially in neuroscience, flexible interfaces provide tremendous possibilities and opportunities to produce reliable, scalable and biocompatible instruments for better exploring neurotransmission and neurological disorders. Of all the types of biomedical instruments such as electroencephalography (EEG) and electrocorticography (ECoG), MEMS-based needle-shape probes have been actively studied in recent years due to their better spatial resolution, selectivity, and sensitivity in chronical invasive physiology monitoring. In order to address the inherent issue of invasiveness that causes tissue damage, research has been made on biocompatible materials, implanting methods and probe structural design. In this dissertation, different types of microfabricated probes for various applications are reviewed. General methods for some key fabrication steps include photolithography patterning, chemical vapor deposition, metal deposition and dry etching are covered in detail. Likewise, three major achievements, which aim to the tagets of flexibility, functionality and mechanical property are introduced and described in detail from chapter 3 to 5. The essential fabrication processes based on XeF2 isotropic silicon etching and parylene conformal deposition are covered in detail, and a set of characterization is summarized