scholarly journals Hydrogel-based piezoresistive sensor for the detection of ethanol

2018 ◽  
Vol 7 (1) ◽  
pp. 219-226 ◽  
Author(s):  
Jan Erfkamp ◽  
Margarita Guenther ◽  
Gerald Gerlach

Abstract. This article describes a low-cost sensor for the detection of ethanol in alcoholic beverages, which combines alcohol-sensitive hydrogels based on acrylamide and bisacrylamide and piezoresistive sensors. For reproducible measurements, the reversible swelling and deswelling of the hydrogel were shown via microscopy. The response time of the sensor depends on the swelling kinetics of the hydrogel. The selectivity of the hydrogel was tested in different alcohols. In order to understand the influence of monomer and crosslinker content on the swelling degree and on the sensitivity of the hydrogels, gels with variable concentrations of acrylamide and bisacrylamide were synthesized and characterized in different aqueous solutions with alcohol contents. The first measurements of such hydrogel-based piezoresistive ethanol sensors demonstrated a high sensitivity and a short response time over several measuring cycles.

2006 ◽  
Vol 45 ◽  
pp. 1828-1833
Author(s):  
Fabio A. Deorsola ◽  
P. Mossino ◽  
Ignazio Amato ◽  
Bruno DeBenedetti ◽  
A. Bonavita ◽  
...  

Nanostructured semiconductor metal oxides have played a central role in the gas sensing research field, because of their high sensitivity, selectivity and low response time. Among all the processes, developed for the synthesis of nanostructured metal oxides, gel combustion seems to be the most promising route due to low-cost precursors and simplicity of the process. It combines chemical gelation and combustion, involving the formation of a gel from an acqueous solution and an exothermic redox reaction, yielding to very porous and softly agglomerated nanopowders. In this work, nanostructured tin oxide, SnO2, and titanium oxide, TiO2, have been synthesized through gel combustion. Powders showed nanometric particle size and high specific surface area. The so-obtained TiO2 and SnO2 nanopowders have been used as sensitive element of resistive λ sensor and ethanol sensor respectively, realized depositing films of nanopowders dispersed in water onto alumina substrates provided with Pt contacts and heater. TiO2-based sensors showed at high temperature good response, fast response time, linearity in a wide range of O2 concentration and long-term stability. SnO2-based sensors have shown high sensitivity to low concentrations of ethanol at moderate temperature.


2018 ◽  
Vol 35 (3) ◽  
pp. 153-157 ◽  
Author(s):  
Samuel Zuk ◽  
Alena Pietrikova ◽  
Igor Vehec

Purpose The purpose of this paper is to analyse the possibilities of mechanical switch replacement by capacitive film touch sensor in applications requiring high reliability and short response time. Advantage of replacing mechanical switch by capacitive touch sensor is no mechanical wear and possible implementation of sensor in application where the switch could not be used or where the flexibility of the sensor substrate is required. The aim of this work is to develop a capacitive touch sensor with the advantage of maximum mechanical resistance, short response time and high sensitivity. Design/methodology/approach Based on various possible sensors layouts, the authors realized 18 different (14 self-capacitance and four mutual capacitance) topologies of capacitive sensor for touch applications. Three different technologies – PCB, LTCC and polymer technology – were used to characterize sensor’s behaviour. For precise characterization of different layouts realized on various substrates, the authors used integrated circuit FDC2214 capacitance-to-digital converter. Findings Sensing range of the capacitive touch (proximity) sensor is affected by the per cent of area covered by the sensor, and it does not depend on topology of sensor. The highest sensing range offers PCB technology. Flexible substrates can be used as proper substituent to rigid PCB. Originality/value The novelty of this work lies in finding the touch capacitive sensors that allow shorter switching times compared to standard mechanical switches.


RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 37085-37092 ◽  
Author(s):  
Ying Yang ◽  
Li Sun ◽  
Xiangting Dong ◽  
Hui Yu ◽  
Tingting Wang ◽  
...  

Fe3O4nanoparticles-decorated reduced graphene oxide nanocomposites have been successfully synthesized using solvothermal-pyrolytic method. They have superior gas sensing performance with low detection limit, high sensitivity and short response time.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1039 ◽  
Author(s):  
Andreia dos Santos ◽  
Nuno Pinela ◽  
Pedro Alves ◽  
Rodrigo Santos ◽  
Elvira Fortunato ◽  
...  

This work describes the production of electronic-skin (e-skin) piezoresistive sensors, which micro-structuration is performed using laser engraved molds. With this fabrication approach, low-cost sensors are easily produced with a tailored performance. Sensors with micro-cones and a high sensitivity of −1 kPa−1 under 600 Pa are more adequate for the blood pressure wave detection, while sensors micro-structured with semi-spheres and a maximum sensitivity of −6 × 10−3 kPa−1 in a large pressure range (1.6 kPa to 100 kPa) are more suitable for robotics and functional prosthesis.


2021 ◽  
Vol 17 (7) ◽  
pp. 1249-1272
Author(s):  
Xiao-Lin Wang ◽  
Xiao Han ◽  
Xiao-Ying Tang ◽  
Xiao-Jun Chen ◽  
Han-Jun Li

With the development of nanomaterials, fluorescent nanoprobes have attracted enormous attention in the fields of chemical sensing, optical materials, and biological detection. In this paper, the advantages of “off–on” fluorescent nanoprobes in disease detection, such as high sensitivity and short response time, are attentively highlighted. The characteristics, sensing mechanisms, and classifications of disease-related target substances, along with applications of these nanoprobes in cancer diagnosis and therapy are summarized systematically. In addition, the prospects of “off–on” fluorescent nanoprobe in disease detection are predicted. In this review, we presented information from all the papers published in the last 5 years discussing “off–on” fluorescent nanoprobes. This review was written in the hopes of being useful to researchers who are interested in further developing fluorescent nanoprobes. The characteristics of these nanoprobes are explained systematically, and data references and supports for biological analysis, clinical drug improvement, and disease detection have been provided appropriately.


RSC Advances ◽  
2019 ◽  
Vol 9 (22) ◽  
pp. 12585-12589 ◽  
Author(s):  
Fa-Heng Zhang ◽  
Rui-Xue Jiang ◽  
Wei Cao ◽  
Bin Du ◽  
Ding-Yuan Cao ◽  
...  

Anisotropic fluorescent nanofibers constructed from the self-assembled perylene bisimide derivative and poly(vinylidene fluoride) show high sensitivity and short response time to aniline vapor.


2020 ◽  
Vol 263 ◽  
pp. 127219
Author(s):  
S. AlFaify ◽  
Mohd. Shkir ◽  
I.S. Yahia ◽  
Mohamed S. Hamdy

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 666 ◽  
Author(s):  
Zhenhua Tang ◽  
Shuhai Jia ◽  
Xuesong Shi ◽  
Bo Li ◽  
Chenghao Zhou

Despite the tremendous efforts dedicated to developing various wearable piezoresistive sensors with sufficient stretchability and high sensitivity, challenges remain pertaining to fabrication scalability, cost, and efficiency. In this study, a facile, scalable, and low-cost coaxial printing strategy is employed to fabricate stretchable and flexible fibers with a core–sheath structure for wearable strain sensors. The highly viscous silica-modified silicone elastomer solution is used to print the insulating sheath layer, and the silicone elastomer solutions containing multi-walled carbon nanotubes (CNTs) are used as the core inks to print the conductive inner layer. With the addition of silica powders as viscosifiers, silica-filled silicone ink (sheath ink) converts to printable ink. The dimensions of the printed coaxial fibers can be flexibly controlled via adjusting the extrusion pressure of the inks. In addition, the electro-mechanical responses of the fiber-shaped strain sensors are investigated. The printed stretchable and wearable fiber-like CNT-based strain sensor exhibits outstanding sensitivities with gauge factors (GFs) of 1.4 to 2.5 × 106, a large stretchability of 150%, and excellent waterproof performance. Furthermore, the sensor can detect a strain of 0.1% and showed stable responses for over 15,000 cycles (high durability). The printed fiber-shaped sensor demonstrated capabilities of detecting and differentiating human joint movements and monitoring balloon inflation. These results obtained demonstrate that the one-step printed fiber-like strain sensors have potential applications in wearable devices, soft robotics, and electronic skins.


2015 ◽  
Vol 3 (5) ◽  
pp. 919-925 ◽  
Author(s):  
Shi-Li Shen ◽  
Xin-Peng Chen ◽  
Xiao-Fan Zhang ◽  
Jun-Ying Miao ◽  
Bao-Xiang Zhao

A novel rhodamine B-based lysosomal pH probe RML was developed. RML responded to acidic pH with short response time, high selectivity and high sensitivity and could detect lysosomal pH change in living cells.


2013 ◽  
Vol 12 (3) ◽  
pp. 239-247

The removal of heavy metals from wastewaters is a matter of paramount importance due to the fact that their high toxicity causes major environmental pollution problems. One of the most efficient, applicable and low cost methods for the removal of toxic metals from aqueous solutions is that of their adsorption on an inorganic adsorbent. In order to achieve high efficiency, it is important to understand the influence of the solution parameters on the extent of the adsorption, as well as the kinetics of the adsorption. In the present work, the adsorption of Cu(II) species onto TiO2 surface was studied. It was found that the adsorption is a rapid process and it is not affected by the value of ionic strength. In addition, it was found that by increasing the pH, the adsorbed amount of Cu2+ ions and the value of the adsorption constant increase, whereas the value of the lateral interaction energy decreases.


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