Low Cost Detection of pH and its Effect on the Capacitive Behavior of Micro-Gap Sensor

2013 ◽  
Vol 832 ◽  
pp. 73-78 ◽  
Author(s):  
Q. Humayun ◽  
U. Hashim ◽  
Tijjani Adam
Keyword(s):  
Ph Value ◽  
Low Cost ◽  
Ph Sensor ◽  
Pattern Transfer ◽  
Ph Sensing ◽  
Sensor Structure ◽  
Gap Spacing ◽  
Photolithography Process ◽  
Electrical Data

The article describes the fabrication and characterization of silver microgap sensor on silicon substrate. By employing cheap photolithography process the proposed microgap sensor has been fabricated. The silver microgap sensor was used for pH sensing, by dropping different pH on microgap surface. To obtain the microgap sensor structure by using AutoCAD software, mask was designed. To maintain high accuracy in pattern transfer the AutoCAD design mask was transferred to chrome glass mask. The fabricated silver microgap pH sensor gap spacing was around 03μm. From the electrical data we conclude that when the pH value varies from acidic to basic (pH 1, pH 2 to pH 11, pH 13) the value of capacitance decreased from 33pF to 8pF. The result shows that the silver microgap pH sensor has the ability to differentiate the acidic pH form basic one. The next part of the research is to decrease the microgap spacing until reach to nanosize spacing, so that can easily used for biosensing application.

scholarly journals Development of a Low-Cost pH Meter for Liquid Chemical Fertilizers

2020 ◽  
Vol 8 (4) ◽  
pp. 840-846
Author(s):  
Muhittin Yağmur Polat ◽  
Abdullah Beyaz ◽  
İbrahim Çilingir
Keyword(s):  
Ph Value ◽  
Low Cost ◽  
Ph Sensor ◽  
Field Application ◽  
Average Error ◽  
Chemical Fertilizers ◽  
Modern Agriculture ◽  
Ph Values ◽  
Water Ph ◽  
Liquid Chemical

Liquid chemical fertilizers are widely used in modern agriculture. The pH values of these fertilizers are important in terms of their effectiveness in the field application and their effect on the soil-water pH balance. Therefore, it is necessary to measure the pH and other properties of liquid fertilizers with fast, practical and inexpensive methods. With the advancing technology, pH value has been started to measure more accurately and efficiently with the help of low-cost devices. In this study, a low-cost pH meter was developed using a low-cost pH sensor, an Arduino UNO R3 microcontroller board, and a software written in the C/C++ programming language. The developed pH meter was used to measure the pH values of liquid chemical fertilizers. Close variations were observed between the values obtained from it and the values measured by an accredited, laboratory-type pH meter. According to the pH measurements of the two pH meters, R2 ranged 88.1% to 99.3%, average error range 0.14 to 0.28, and average error percentage ranged 1.56% to 6.81% for three different types of liquid fertilizers. In light of these results, it was shown that the developed low-cost pH meter can be useful for practical pH measurement applications.

scholarly journals Systematic Evaluation of Arduino Open Source for Automation and Control of Chemical Processes

2020 ◽  
Vol 10 (2) ◽  
pp. 2258-2271
Keyword(s):  
Open Source ◽  
Chemical Process ◽  
Ph Value ◽  
Low Cost ◽  
Ph Sensor ◽  
Chemical Processes ◽  
Systematic Evaluation ◽  
Feedback Signal ◽  
Automation And Control ◽  
And Control

Inceptions for chemical process automation are presented in this study. A chemical process demonstrated by neutralization reaction was designed, built, and tested experimentally towards evaluating automation and control algorithms through the Arduino Mega platform. The main objective parameter in this work was selected to be the product pH value, which was evaluated based on several scenarios that targeted various changes in direct and indirect effects. Two main branched ideas were investigated in this study; the first was dealt with the application of Arduino board in the automation of chemical process; the second was dedicated to studying integration of Arduino board in controlling the targeted pH parameter in the product side. Upon examining different automation scenarios, an algorithm was developed to approach the product quality of specific pH and temperature efficiently. The automation algorithm was further developed by integrating the process dynamics and control concepts towards speeding up the pH set point's reach. To make this happen, the pump's speed was corrected and tuned based on the feedback signal from the pH sensor. Consequently, the setpoint was reached in shorter periods, attaining considerable savings in time (≈ 35%). Based on the study outcomes, it is believed that Arduino open source is a challenging and promising low-cost platform, proved useful for mimicking control and automation of chemical processes.

scholarly journals TiO2 Nano Flowers Based EGFET Sensor for pH Sensing

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 251
Author(s):  
Chih-Chiang Yang ◽  
Kuan-Yu Chen ◽  
Yan-Kuin Su
Keyword(s):  
Ph Value ◽  
Ph Sensor ◽  
High Sensitivity ◽  
Experimental Result ◽  
Ph Sensing ◽  
Voltage Reference ◽  
Ph Sensors ◽  
Oxide Substrate ◽  
Ph Range ◽  
The Relationship

In this study, pH sensors were successfully fabricated on a fluorine-doped tin oxide substrate and grown via hydrothermal methods for 8 h for pH sensing characteristics. The morphology was obtained by high-resolution scanning electron microscopy and showed randomly oriented flower-like nanostructures. The TiO2 nanoflower pH sensors were measured over a pH range of 2–12. Results showed a high sensitivity of the TiO2 nano-flowers pH sensor, 2.7 (μA)1/2/pH, and a linear relationship between IDS and pH (regression of 0.9991). The relationship between voltage reference and pH displayed a sensitivity of a 46 mV/pH and a linear regression of 0.9989. The experimental result indicated that a flower-like TiO2 nanostructure extended gate field effect transistor (EGFET) pH sensor effectively detected the pH value.

scholarly journals Graphene Channel Liquid Container Field Effect Transistor as pH Sensor

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xin Li ◽  
Junjie Shi ◽  
Junchao Pang ◽  
Weihua Liu ◽  
Hongzhong Liu ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistor ◽  
Ph Value ◽  
Ph Sensor ◽  
Drain Current ◽  
Fast Response ◽  
Monolayer Graphene ◽  
Ph Sensing ◽  
Order Of Magnitude ◽  
Effect Transistor

Graphene channel liquid container field effect transistor pH sensor with interdigital microtrench for liquid ion testing is presented. Growth morphology and pH sensing property of continuous few-layer graphene (FLG) and quasi-continuous monolayer graphene (MG) channels are compared. The experiment results show that the source-to-drain current of the graphene channel FET has a significant and fast response after adsorption of the measured molecule and ion at the room temperature; at the same time, the FLG response time is less than 4 s. The resolution of MG (0.01) on pH value is one order of magnitude higher than that of FLG (0.1). The reason is that with fewer defects, the MG is more likely to adsorb measured molecule and ion, and the molecules and ions can make the transport property change. The output sensitivities of MG are from 34.5% to 57.4% when the pH value is between 7 and 8, while sensitivity of FLG is 4.75% when thepH=7. The sensor fabrication combines traditional silicon technique and flexible electronic technology and provides an easy way to develop graphene-based electrolyte gas sensor or even biological sensors.

scholarly journals A 7 μW Offset- and Temperature-Compensated pH-to-Digital Converter

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Saleh Heidary Shalmany ◽  
Matthias Merz ◽  
Ali Fekri ◽  
Zu-yao Chang ◽  
Romano J. O. M. Hoofman ◽  
...  
Keyword(s):  
Low Cost ◽  
Ph Sensor ◽  
Environmental Parameters ◽  
Cmos Process ◽  
Ph Sensing ◽  
Compensation Scheme ◽  
Sensing Element ◽  
Cross Sensitivity ◽  
Front End ◽  
Delta Sigma

This paper demonstrates a micropower offset- and temperature-compensated smart pH sensor, intended for use in battery-powered RFID systems that monitor the quality of perishable products. Low operation power is essential in such systems to enable autonomous logging of environmental parameters, such as the pH level, over extended periods of time using only a small, low-cost battery. The pH-sensing element in this work is an ion-sensitive extended-gate field-effect transistor (EGFET), which is incorporated in a low-power sensor front-end. The front-end outputs a pH-dependent voltage, which is then digitized by means of a co-integrated incremental delta-sigma ADC. To compensate for the offset and temperature cross-sensitivity of the EGFET, a compensation scheme using a calibration process and a temperature sensor has been devised. A prototype chip has been realized in a 0.16 μm CMOS process. It occupies 0.35 × 3.9 mm2 of die area and draws only 4 μA from a 1.8 V supply. Two different types of custom packaging have been used for measurement purposes. The pH sensor achieves a linearity of better than ±0.1 for pH values ranging from 4 to 10. The calibration and compensation scheme reduces errors due to temperature cross-sensitivity to less than ±0.1 in the temperature range of 6°C to 25°C.

scholarly journals Fabrication And pH Sensing Characteristics Measurement of Back Gate ZnO Thin Film Planar FET

2021 ◽  
Author(s):  
Ankita Porwal ◽  
Chitrakant Sahu
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Surface Characterization ◽  
Ph Value ◽  
Ph Sensor ◽  
Ph Sensitivity ◽  
Voltage Sensitivity ◽  
Zno Thin Film ◽  
Ph Sensing ◽  
Back Gate

Abstract Here in we demonstrate the design of a low- cost zinc oxide (ZnO) thin-film planar transistor-based pH sensor controlled by the bottom gate fabricated by a fairly simple fabrication approach. The performance of the fabricated device is evaluated by electrical as well as surface characterization. The surface morphology is analyzed by scanning electron microscope (SEM) and atomic force microscopy (AFM) and it shows surface properties that are essential for a device to function as a pH sensor. The fabricated thin-film FET comprises Zinc Oxide (ZnO) as a channel layer of length 6 µm and thickness 200 nm, Silicon Nitride (Si3N4) as a pas- sivation layer, and Aluminum (Al) as a contact layer. The effect on pH sensitivity for varied channel lengths (6 µm, 12 µm, and 15 µm) is also examined and opti- mum results have been achieved at channel length = 6 µm. The change in threshold voltage (ΔVth) & change in current (ΔImax) are used as a sensing metrics to an- alyze the sensing performance of the device. The device shows excellent pH sensitivity in terms of average cur- rent and average voltage sensitivity 120.97 mA/pH and 97.85 mv/pH respectively at pH ranging from 3.2 to 11.1 with best pH stability (linearity) for pH value 4 to 10. The voltage sensitivity is higher than the Nernstian value (59 mv/pH) at room temperature.

scholarly journals Fabrication and Characterization of In0.9Ga0.1O EGFET pH Sensors

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 929
Author(s):  
Chia-Hsun Chen ◽  
Shu-Bai Liu ◽  
Sheng-Po Chang
Keyword(s):  
Ph Value ◽  
High Sensitivity ◽  
Rf Magnetron Sputtering ◽  
Voltage Sensitivity ◽  
Ph Sensing ◽  
Ph Sensors ◽  
Current Sensitivity ◽  
Saturation Region ◽  
Sensing Membrane

In this study, the In0.9Ga0.1O sensing membrane were deposited by using the RF magnetron sputtering at room temperature and combined with commercial MOSFETs as the extended gate field effect transistor (EGFET) pH sensors. The sensing performance of the In0.9Ga0.1O EGFET pH sensors were measured and analyzed in the pH value of range between 2 to 12. In the saturation region, the pH current sensitivity calculated from the linear relationship between the and pH value was approximately 56.64 μA/pH corresponding to the linearity of 97.8%. In the linear region, the pH voltage sensitivity exhibited high sensitivity and linearity of 43.7 mV/pH and 96.3%, respectively. The In0.9Ga0.1O EGFET pH sensors were successfully fabricated and exhibited great linearity. The analyzed results indicated that the In0.9Ga0.1O was a robust material as a promising sensing membrane and effectively used for pH sensing detection application.

scholarly journals Microstructure and Thermoelectric Properties of (Bi0.48Sb1.52)Te3 Thick Films Prepared with Tape Casting Method

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Low Cost ◽  
Thick Films ◽  
Tape Casting ◽  
Casting Process ◽  
Casting Method ◽  
Glass Substrates ◽  
Conductive Films ◽  
Casting Technology

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.

scholarly journals Microscopic Image Segmentation and Morphological Characterization of Novel Chitosan/Silica Nanoparticle/Nisin Films Using Antimicrobial Technique for Blueberry Preservation

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 303
Author(s):  
Rokayya Sami ◽  
Schahrazad Soltane ◽  
Mahmoud Helal
Keyword(s):  
Ph Value ◽  
Silica Nanoparticle ◽  
Morphological Characterization ◽  
Aerobic Bacteria ◽  
Nano Materials ◽  
Elongation At Break ◽  
Stable Suspension ◽  
Average Size ◽  
Material Ductility

In the current work, the characterization of novel chitosan/silica nanoparticle/nisin films with the addition of nisin as an antimicrobial technique for blueberry preservation during storage is investigated. Chitosan/Silica Nanoparticle/N (CH-SN-N) films presented a stable suspension as the surface loads (45.9 mV) and the distribution was considered broad (0.62). The result shows that the pH value was increased gradually with the addition of nisin to 4.12, while the turbidity was the highest at 0.39. The content of the insoluble matter and contact angle were the highest for the Chitosan/Silica Nanoparticle (CH-SN) film at 5.68%. The use of nano-materials in chitosan films decreased the material ductility, reduced the tensile strength and elongation-at-break of the membrane. The coated blueberries with Chitosan/Silica Nanoparticle/N films reported the lowest microbial contamination counts at 2.82 log CFU/g followed by Chitosan/Silica Nanoparticle at 3.73 and 3.58 log CFU/g for the aerobic bacteria, molds, and yeasts population, respectively. It was observed that (CH) film extracted 94 regions with an average size of 449.10, at the same time (CH-SN) film extracted 169 regions with an average size of 130.53. The (CH-SN-N) film presented the best result at 5.19%. It could be observed that the size of the total region of the fruit for the (CH) case was the smallest (1663 pixels), which implied that the fruit lost moisture content. As a conclusion, (CH-SN-N) film is recommended for blueberry preservation to prolong the shelf-life during storage.

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