Highly selective piezoresistive sensor for mercury (Hg2+) ions detection using mercaptosuccinic acid-functionalized microcantilevers with cross-linked pyridinedicarboxylic acid

Sensor Review ◽  
2020 ◽  
Vol 40 (5) ◽  
pp. 543-558 ◽  
Author(s):  
Dinesh Ramkrushna Rotake ◽  
Anand Darji ◽  
Nitin S. Kale
Keyword(s):  
Thin Film ◽  
Limit Of Detection ◽  
Human Life ◽  
Microfluidic System ◽  
Micro Electro Mechanical Systems ◽  
Content Type ◽  
Mercaptosuccinic Acid ◽  
Piezoresistive Sensor ◽  
Field Investigations ◽  
Pyridinedicarboxylic Acid

Purpose This paper aims to report an insightful portable microfluidic system for rapid and selective sensing of Hg2+ in the picomolar (pM) concentration using microcantilever-based piezoresistive sensor. The detection time for various laboratory-based techniques is generally 12–24 h. The majority of modules used in the proposed platform are battery oriented; therefore, they are portable and handy to carry-out on-field investigations. Design/methodology/approach In this study, the authors have incorporated the benefit of three technologies, i.e. thin-film, nanoparticles (NPs) and micro-electro-mechanical systems, to selectively capture the Hg2+ at the pM concentration. The morphology and topography of the proposed sensor are characterized using field emission scanning electron microscopy and verification of the experimental results using energy dispersive X-ray. Findings The proposed portable microfluidic system is able to perform the detection in 5 min with a limit of detection (LOD) of 0.163 ng (0.81 pM/mL) for Hg2+, which perfectly describes its excellent performance over other reported techniques. Research limitations/implications A microcantilever-based technology is perfect for on-site detection, and a LOD of 0.163 ng (0.81 pM/mL) is outstanding compared to other techniques, but the fabrication of microcantilever sensor is complex. Originality/value Many researchers used NPs for heavy metal ions sensing, but the excess usage and industrialization of NPs are rapidly expanding harmful consequences on the human life and nature. Also, the LOD of the NPs-based method is limited to nanomolar concentration. The suggested microfluidic system used the benefit of thin-film and microcantilever devices to provide advancement over the NPs-based approach and it has a selective sensing in pM concentration.

Design of microfluidic experimental setup for the detection of heavy metal ions using piezoresistive BioMEMS sensor

2019 ◽  
Vol 37 (1) ◽  
pp. 10-28 ◽  
Author(s):  
Dinesh Ramkrushna Rotake ◽  
Anand D. Darji ◽  
Nitin S. Kale
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Error Detection ◽  
Heavy Metal Ions ◽  
Field Experiments ◽  
Limit Of Detection ◽  
Experimental Setup ◽  
Content Type ◽  
Experimental Platform ◽  
Piezoresistive Sensor

Purpose This paper aims to propose a new microfluidic portable experimental platform for quick detection of heavy metal ions (HMIs) in picomolar range. The experimental setup uses a microfabricated piezoresistive sensor (MPS) array of eight cantilevers with ion-selective self-assembled monolayer's (SAM). Design/methodology/approach Most of the components used in this experimental setup are battery operated and, hence, portable to perform the on-field experiments. HMIs (antigen) and thiol-based SAM (antibody) interaction start bending the microcantilever. This results in a change of resistance, which is directly proportional to the surface stress produced due to the mass of targeted HMIs. The authors have used Cysteamine and 4-Mercaptobenzoic acid as a thiol for creating SAM to test the sensitivity and identify the suitable thiol. Some of the cantilevers are blocked using acetyl chloride to use as a reference for error detection. Findings The portable experimental platform achieves very small detection time of 10-25 min with a lower limit of detection (LOD) 0.762 ng (6.05 pM) for SAM of Cysteamine and 4-Mercaptobenzoic acid to detect Mn2+ ions. This technique has excellent potential and capability to selectively detect Hg2+ ions as low as 2.43 pM/mL using SAM of Homocysteine (Hcys)-Pyridinedicarboxylic acid (PDCA). Research limitations/implications As microcantilever is very thin and fragile, it is challenging to apply a surface coating to have selective detection using Nanadispenser. Some of the cantilevers get broken during this process. Originality/value The excessive use and commercialization of NPs are quickly expanding their toxic impact on health and the environment. Also, LOD is limited to nanomolar range. The proposed method used the combination of thin-film, NPs, and MEMS-based technology to overcome the limitation of NPs-based technique and have picomolar range of HMIs detection.

Microfabrication of Si3N4-polyimide membrane for thermo-pneumatic actuator

2015 ◽  
Vol 32 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Norihan Abdul Hamid ◽  
J. Yunas ◽  
B. Yeop Majlis ◽  
A.A. Hamzah ◽  
B. Bais
Keyword(s):  
Thin Film ◽  
Temperature Increase ◽  
Adhesive Bonding ◽  
Nitride Layer ◽  
Pneumatic Actuator ◽  
Heat Condition ◽  
Micro Electro Mechanical Systems ◽  
Content Type ◽  
Lab On Chip ◽  
Polyimide Membrane

Purpose – The purpose of this paper is to discuss the fabrication technology and test of thermo-pneumatic actuator utilizing Si3N4-polyimide thin film membrane. Thin film polyimide membrane capped with Si3N4 thin layer is used as actuator membrane which is able to deform through thermal forces inside an isolated chamber. The fabricated membrane will be suitable for thermo-pneumatic-based membrane actuation for lab-on-chip application. Design/methodology/approach – The actuator device consisting of a micro-heater, a Si-based micro-chamber and a heat-sensitive square-shaped membrane is fabricated using surface and bulk-micromachining process, with an additional adhesive bonding process. The polyimide membrane is capped with a thin silicon nitride layer that is fabricated by using etch stop technique and spin coating. Findings – The deformation property of the membrane depend on the volumetric expansion of air particles in the heat chamber as a result of temperature increase generated from the micro-heater inside the chamber. Preliminary testing showed that the fabricated micro-heater has the capability to generate heat in the chamber with a temperature increase of 18.8 °C/min. Analysis on membrane deflection against temperature increase showed that heat-sensitive thin polyimide membrane can perform the deflection up to 65 μm for a temperature increase of 57°C. Originality/value – The dual layer polyimide capped with Si3N4 was used as the membrane material. The nitride layer allowed the polyimide membrane for working at extreme heat condition. The process technique is simple implementing standard micro-electro-mechanical systems process.

Thin-film based sensor for the selective detection of mercury (Hg2+) ions at the picomolar range

Sensor Review ◽  
2020 ◽  
Vol 40 (4) ◽  
pp. 485-495 ◽  
Author(s):  
Dinesh Ramkrushna Rotake ◽  
Anand Darji ◽  
Jitendra Singh
Keyword(s):  
Thin Film ◽  
Real Time ◽  
Water Samples ◽  
Field Experiments ◽  
Limit Of Detection ◽  
Selective Detection ◽  
Film Sensor ◽  
Content Type ◽  
Raman Scattering Spectroscopy ◽  
Thin Film Sensor

Purpose The purpose of this paper is a new thin-film based sensor proposed for sensitive and selective detection of mercury (Hg2+) ions in water. The thin-film platform is easy to use and quick for heavy metal ions (HMIs) detection in the picomolar range. Ion-selective self-assembled monolayer's (SAM) of thiol used for the detection of HMIs above the Au/Ti top surface. Design/methodology/approach A thin-film based platform is suitable for the on-field experiments and testing of water samples. HMIs (antigen) and thiol-based SAM (antibody) interaction results change in surface morphology and topography. In this study, the authors have used different characterization techniques to check the selectivity of the proposed method. This change in the morphology and topography of thin-film sensor checked with Fourier-transform infrared spectroscopy, surface-enhanced Raman scattering spectroscopy, atomic force microscopy and scanning electron microscopy with energy dispersive x-ray analysis used for high-resolution images. Findings This thin-film based platform is straightforward to use and suitable for real-time detection of HMIs at the picomolar range. This thin-film based sensor platform capable of achieving a lower limit of detection (LOD) 27.42 ng/mL (136.56 pM) using SAM of Homocysteine-Pyridinedicarboxylic acid to detect Hg2+ ions. Research limitations/implications A thin-film based technology is perfect for real-time testing and removal of HMIs, but the LOD is higher as compared to microcantilever-based devices. Originality/value The excessive use and commercialization of nanoparticle (NPs) are quickly expanding their toxic impact on health and the environment. The proposed method used the combination of thin-film and NPs, to overcome the limitation of NPs-based technique and have picomolar (136.56 pM) range of HMIs detection. The proposed thin-film-based sensor shows excellent repeatability and the method is highly reliable for toxic Hg2+ ions detection. The main advantage of the proposed thin-film sensor is its ability to selectively remove the Hg2+ ions from water samples just like a filter and a sensor for detection at picomolar range makes this method best among the other current-state of the art techniques.

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

Environmental tests of embedded thin- and thick-film resistors in comparison to chip resistors

Circuit World ◽  
2014 ◽  
Vol 40 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Wojciech Steplewski ◽  
Andrzej Dziedzic ◽  
Janusz Borecki ◽  
Grazyna Koziol ◽  
Tomasz Serzysko
Keyword(s):  
Thin Film ◽  
Thick Film ◽  
Electrical Resistance ◽  
Printed Circuit Boards ◽  
Base Material ◽  
Forming Process ◽  
Content Type ◽  
Thin Film Resistors ◽  
Embedded Resistors ◽  
The Impact

Purpose – The purpose of this paper is to investigate the influence of parameters of embedded resistive elements manufacturing process as well as the influence of environmental factors on their electrical resistance. The investigations were made in comparison to the similar constructions of discrete chip resistors assembled to standard printed circuit boards (PCBs). Design/methodology/approach – The investigations were based on the thin-film resistors made of NiP alloy, thick-film resistors made of carbon or carbon-silver inks as well as chip resistors in 0402 and 0603 packages. The polymer thick-film resistive films were screen-printed on the several types finishing materials of contact terminations such as copper, silver, and gold. To determine the sensitivity of embedded resistors versus standard assembled chip resistors on environmental exposure, the climatic chamber was used. The measurements of resistance were carried out periodically during the tests, and after the exposure cycles. Findings – The results show that the change of electrical resistance of embedded resistors, in dependence of construction and base material, is different and mainly not exceed the range of 3 per cent. The achieved results in reference to thin-film resistors are comparable with results for standard chip resistors. However, the results that were obtained for thick-film resistors with Ag and Ni/Au contacts are similar. It was not found the big differences between resistors with and without conformal coating. Research limitations/implications – The studies show that embedded resistors can be used interchangeably with chip resistors. It allows to save the area on the surface of PCB, occupied by these passive elements, for assembly of active elements (ICs) and thus enable to miniaturization of electronic devices. But embedding of passive elements into PCB requires to tackle the effect of each forming process steps on the operational properties. Originality/value – The technique of passive elements embedding into PCB is generally known; however, there are no detailed reports on the impact of individual process steps and environmental conditions on the stability of their electrical resistance. The studies allow to understand the importance of each factor process and the mechanisms of operational properties changes depending on the used materials.

Confucian Modernity, Ultimacies, and Transcendence

2021 ◽  
Vol 75 (3/4) ◽  
pp. 397-428 ◽  
Author(s):  
Robert Cummings Neville
Keyword(s):  
Historical Perspective ◽  
Human Life ◽  
Ultimate Reality ◽  
Content Type ◽  
Confucian Philosophy

Abstract I want to engage Taylor with a comparative Confucian vision of modernity. In order to do this, I need to present a metaphysics which can serve as a framework for comparisons necessary for a global philosophical historical perspective on modernity and transcendence and in which, in particular, I can represent both Christian and Confucian categories as alternative specifications of ultimate reality. Using non-personalistic metaphors of spontaneous emergence and stressing (dis)harmonies, Confucian philosophy gives its own specification of the ultimate conditions of human life. This will allow me to sketch how Confucian modernists might engage with modernity. I will thus defend in Confucian terms Taylor’s claim that genuine religious transcendence is possible within the conditions of modernity.

Postmoney theory: value function in the domain of postmoney

foresight ◽  
2018 ◽  
Vol 20 (5) ◽  
pp. 554-570
Author(s):  
Boyan Christov Ivantchev
Keyword(s):  
Social Impact ◽  
Value Function ◽  
Human Life ◽  
Intrinsic Value ◽  
Panel Study ◽  
Economic Research ◽  
Strong Base ◽  
Content Type ◽  
A Value ◽  
First Time

Purpose The purpose of this study is to research the latest quantitative and qualitative transformations of money and its interaction with the market economy and societies in terms of their influence on the inner nature of money and its transformation from a simple tool to an aim per se, i.e. postmoney. Transforming the perception of the intrinsic value and “soul” of the money into the postmoney, influenced by the rising longevity and wide expectation for the ability to scientifically prolong the human life, will be discussed. This transformation will be confirmed by analysing the results from a national representative sociological survey (panel study with sample size n = 1,000). Design/methodology/approach The author uses the following philosophical methodological approaches – comparative-constructive, phenomenological, cognitive and deconstructive analysis. Findings The objective and qualitative reasons offered by the postmoney theory (PMT) for the transformation of money into postmoney, are related to the being of temporality, as well as to technologization and the sixth factor of production, scientific exponentiality and mental changes in the human being. A current postmoney survey gives a strong base to believe that the perception of an intrinsic value of postmoney changes the shape of a value function – from logarithmic to linear or even stochastic. This is the reason to believe that increasing of a postmoney quantity will lead to a qualitative transformation and psychological increase of postmoney sensitivity. Research limitations/implications The author intends to expand the postmoney survey on the international level so to confirm local findings. Practical implications Postmoney survey might be used as a powerful tool in creating and legalizing non-monistic money based on blockchain technologies and philosophical and socio-economic research of the postmoney issue. Social implications The future of money is of great importance for the exponentiality of the socio-economic environment and societies. Social impact of the money will be inevitably rising in the domain of postmoney perception. Originality/value The author of the current paper coined for the first-time notion of postmoney and now is expanding research developing PMT. As per the best knowledge of the author, shape of the curve of value function was not questioned and believes it might be of help to better understand the money phenomenon.

A self-developed indoor three-dimensional pedestrian localization platform based on MEMS sensors

Sensor Review ◽  
2015 ◽  
Vol 35 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Shengbo Sang ◽  
Ruiyong Zhai ◽  
Wendong Zhang ◽  
Qirui Sun ◽  
Zhaoying Zhou
Keyword(s):  
Low Cost ◽  
Angular Rate ◽  
Three Dimensional ◽  
Dead Reckoning ◽  
Rate Data ◽  
Mems Sensors ◽  
Micro Electro Mechanical Systems ◽  
Content Type ◽  
Position Errors ◽  
Low Performance

Purpose – This study aims to design a new low-cost localization platform for estimating the location and orientation of a pedestrian in a building. The micro-electro-mechanical systems (MEMS) sensor error compensation and the algorithm were improved to realize the localization and altitude accuracy. Design/methodology/approach – The platform hardware was designed with common low-performance and inexpensive MEMS sensors, and with a barometric altimeter employed to augment altitude measurement. The inertial navigation system (INS) – extended Kalman filter (EKF) – zero-velocity updating (ZUPT) (INS-EKF-ZUPT [IEZ])-extended methods and pedestrian dead reckoning (PDR) (IEZ + PDR) algorithm were modified and improved with altitude determined by acceleration integration height and pressure altitude. The “AND” logic with acceleration and angular rate data were presented to update the stance phases. Findings – The new platform was tested in real three-dimensional (3D) in-building scenarios, achieved with position errors below 0.5 m for 50-m-long route in corridor and below 0.1 m on stairs. The algorithm is robust enough for both the walking motion and the fast dynamic motion. Originality/value – The paper presents a new self-developed, integrated platform. The IEZ-extended methods, the modified PDR (IEZ + PDR) algorithm and “AND” logic with acceleration and angular rate data can improve the high localization and altitude accuracy. It is a great support for the increasing 3D location demand in indoor cases for universal application with ordinary sensors.

Electrostatic charge interaction: a case study on tapered PMMA fiber for calcium nitrate detection

Sensor Review ◽  
2014 ◽  
Vol 34 (4) ◽  
pp. 424-427 ◽  
Author(s):  
M. Batumalay ◽  
A. Lokman ◽  
H.A. Rahman ◽  
S.W. Harun ◽  
H. Ahmad
Keyword(s):  
Limit Of Detection ◽  
Nitrate Solution ◽  
Calcium Nitrate ◽  
Fiber Optic Sensor ◽  
Multimode Fiber ◽  
Working Mechanism ◽  
Content Type ◽  
Charge Interaction ◽  
Chemical Solutions

Purpose – This paper aims to propose and demonstrate a simple fiber optic sensor using a tapered plastic multimode fiber as a probe for measurement of calcium nitrate concentrations in de-ionized water. Design/methodology/approach – The working mechanism is based on the observed increment in the transmission of the sensor that is immersed in calcium nitrate solution of higher concentration. The tapering of the plastic fiber is carried out by etching method using acetone, sand paper and de-ionized water. Findings – Tapered fiber with diameter 0.45 mm gives the highest sensitivity of 0.028 mV/% due to better interaction between the evanescent field and the calcium nitrate solution with a good slope linearity of more than 98 per cent for a 1.07 per cent limit of detection in a straight probe arrangement. The use of calcium and nitrate ions within the sensing medium demonstrates the strong dependency of the sensor output trend on the electrolytic nature of the chemical solutions. Originality/value – Demonstration of tapered plastic multimode fiber sensor probe for measurement electrolytic chemical solutions.

scholarly journals Detection and Differentiation of Avian Mycoplasmas by Surface-Enhanced Raman Spectroscopy Based on a Silver Nanorod Array

2011 ◽  
Vol 78 (6) ◽  
pp. 1930-1935 ◽  
Author(s):  
Suzanne L. Hennigan ◽  
Jeremy D. Driskell ◽  
Naola Ferguson-Noel ◽  
Richard A. Dluhy ◽  
Yiping Zhao ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Sensitivity And Specificity ◽  
Limit Of Detection ◽  
Direct Detection ◽  
Nanorod Array ◽  
Surface Enhanced Raman Spectroscopy ◽  
Mycoplasma Species ◽  
Content Type ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

ABSTRACTMycoplasma gallisepticumis a bacterial pathogen of poultry that is estimated to cause annual losses exceeding $780 million. The National Poultry Improvement Plan guidelines recommend regular surveillance and intervention strategies to containM. gallisepticuminfections and ensure mycoplasma-free avian stocks, but several factors make detection ofM. gallisepticumand diagnosis ofM. gallisepticuminfection a major challenge. Current techniques are laborious, require special expertise, and are typically plagued by false results. In this study, we describe a novel detection strategy which uses silver nanorod array–surface-enhanced Raman spectroscopy (NA-SERS) for direct detection of avian mycoplasmas. As a proof of concept for use in avian diagnostics, we used NA-SERS to detect and differentiate multiple strains of avian mycoplasma species, includingAcholeplasma laidlawii,Mycoplasma gallinarum,Mycoplasma gallinaceum,Mycoplasma synoviae, andM. gallisepticum, including vaccine strains 6/85, F, and ts-11. Chemometric multivariate analysis of spectral data was used to classify these species rapidly and accurately, with >93% sensitivity and specificity. Furthermore, NA-SERS had a lower limit of detection that was 100-fold greater than that of standard PCR and comparable to that of real-time quantitative PCR. Detection ofM. gallisepticumin choanal cleft swabs from experimentally infected birds yielded good sensitivity and specificity, suggesting that NA-SERS is applicable for clinical detection.

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