J.K. Atkinson, M. Glanc, P. Boltryk, M. Sophocleous and E. Garcia‐Breijo
The purpose of this paper is to show how the fabrication parameters of screen‐printed thick‐film reference electrodes have been experimentally varied and their effect on device…
Abstract
Purpose
The purpose of this paper is to show how the fabrication parameters of screen‐printed thick‐film reference electrodes have been experimentally varied and their effect on device characteristics investigated.
Design/methodology/approach
The tested devices were fabricated as screen‐printed planar structures consisting of a silver back contact, a silver/silver chloride interfacial layer and a final salt reservoir layer containing potassium chloride. The fabrication parameters varied included deposition method and thickness, salt concentration and binder type used for the final salt reservoir layer. Characterisation was achieved by monitoring the electrode potentials as a function of time following initial immersion in test fluids in order to ascertain initial hydration times, subsequent electrode drift rates and useful lifetime of the electrodes. Additionally, the effect of fabrication parameter variation on electrode stability and their response time in various test media was also investigated.
Findings
Results indicate that, although a trade‐off exists between hydration times and drift rate that is dependent on device thickness, the initial salt concentration levels and binder type also have a significant bearing on the practical useful lifetime. Generally speaking, thicker devices take longer to hydrate but have longer useful lifetimes in a given range of chloride environments. However, the electrode stability and response time is also influenced by the type of binder material employed for the final salt reservoir layer.
Originality/value
The reported results help to explain better the behaviour of thick‐film reference electrodes and contribute towards the optimisation of their design and fabrication for use in solid‐state chemical sensors.
Details
Keywords
Mansoor Ahmad, Ayhan Bozkurt and Omid Farhanieh
This paper aims to Separation and sorting of biological cells is desirable in many applications for analyzing cell properties, such as disease diagnostics, drugs delivery…
Abstract
Purpose
This paper aims to Separation and sorting of biological cells is desirable in many applications for analyzing cell properties, such as disease diagnostics, drugs delivery, chemical processing and therapeutics.
Design/methodology/approach
Acoustic energy-based bioparticle separation is a simple, viable, bio-compatible and contact-less technique using, which can separate the bioparticles based on their density and size, with-out labeling the sample particles.
Findings
Conventionally available bioparticle separation techniques as fluorescence and immunomagnetic may cause a serious threat to the life of the cells due to various compatibility issues. Moreover, they also require an extra pre-processing labeling step. Contrarily, label-free separation can be considered as an alternative solution to the traditional bio-particle separation methods, due to their simpler operating principles and lower cost constraints. Acoustic based particle separation methods have captured a lot of attention among the other reported label-free particle separation techniques because of the numerous advantages it offers.
Practical implications
This study tries to briefly cover the developments of different acoustic-based particle separation techniques over the years. Unlike the conventional surveys on general bioparticles separation, this study is focused particularly on the acoustic-based particle separation. The study would provide a comprehensive guide for the future researchers especially working in the field of the acoustics, in studying and designing the acoustic-based particle separation techniques.
Originality/value
The study insights a brief theory of different types of acoustic waves and their interaction with the bioparticles is considered, followed by acoustic-based particle separation devices reported till the date. The integration of acoustic-based separation techniques with other methods and with each other is also discussed. Finally, all major aspects like the approach, and productivity, etc., of the adopted acoustic particle separation methods are sketched in this article.
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Keywords
J.K. Atkinson, M. Glanc, M. Prakorbjanya, M. Sophocleous, R.P. Sion and E. Garcia‐Breijo
The purpose of this paper is to report thick film environmental and chemical sensor arrays designed for deployment in both subterranean and submerged aqueous applications.
Abstract
Purpose
The purpose of this paper is to report thick film environmental and chemical sensor arrays designed for deployment in both subterranean and submerged aqueous applications.
Design/methodology/approach
Various choices of materials for reference electrodes employed in these different applications have been evaluated and the responses of the different sensor types are compared and discussed.
Findings
Results indicate that the choice of binder materials is critical to the production of sensors capable of medium term deployment (e.g. several days) as the binders not only affect the tradeoff between hydration time and drift but also have a significant bearing on device sensitivity and stability. Sensor calibration is shown to remain an issue with long‐term deployments (e.g. several weeks) but this can be ameliorated in the medium term with the use of novel device fabrication and packaging techniques.
Originality/value
The reported results indicate that is possible through careful choice of materials and fabrication methods to achieve near stable thick film reference electrodes that are suitable for use in solid state chemical sensors in a variety of different application areas.