Optical microbottle resonator with polyvinyl alcohol coating for sodium alginate concentration sensing

The research paper defined the effect of polyvinyl alcohol (PVA) coating on optical microbottle resonator (MBR) for sodium alginate concentration sensor. The resonator made from silica fiber SMF28 used a technique known as “soften-and compress”. The MBRs size is based on the three parameters, which is bottle diameter (Db), stem diameter (Ds) and bottle length (Lb). The MBR was then coated with PVA and named MBR-PVA-A, MBR-PVA-B and MBR-PVA-C. The coated MBR-PVA was then coupled with microfiber for characterisation and able to have Q-factor >105 for all conditions. The MBR-PVAs were then used for the sodium alginate sensor with liquid concentrations ranging from 1% to 6%. The MBR-PVAs performance is ultimately excellent, where the results are based on transmitted power and wavelength shift analysis. The MBR-PVAs are promising as sodium alginate concentration sensors by the sensitivity, linearity, stability, and repeatability performance

Formaldehyde sensing using tapered u-shape plastic optical fiber coated with zinc oxide nanorods

Continuous exposure to formaldehyde may cause injury to the central nervous, respiratory, blood, and immunological systems. Tapered U-shape plastic optical fiber (POF) coated with zinc oxide nanorods was evaluated at wavelength of 645 nm for formaldehyde vapor sensing within a concentration range from 5% to 20%. The tapered POF with 500 µm waist diameter was prepared using chemical etching technique. Zinc oxide nanorods were synthesized using hydrothermal method and growth for 12 hours on the tapered POF. The proposed sensor exhibited a good response to formaldehyde concentration ranging from 5% to 20% with sensitivity and linearity measured to be 0.00543V/% and 98.58%, respectively. Excellent measurement stability was observed when the concentrations from 5% and above are maintain over a 600 second period. Highest difference voltage was produced by 0.0958V due to the more scattering effect of ZnO nanorods at 20% of formaldehyde concentration. This proposed sensor might be also used to detect air pollution produced not just by formaldehyde vapor, but also by other dangerous or poisonous vapors or gases

ZnO Nanorods Coated Microfiber Loop Resonator For Relative Humidity Sensing

This paper reported a new humidity sensor, employing microfiber loop resonator (MLR) coated with Zinc Oxide (ZnO) as a probe. The MLR was constructed from a silica tapered fiber with a waist diameter of 7 µm, which was prepared using flame brushing technique. The self-touching loop was coated by ZnO using sol–gel method. A significant response to humidity changes from 35%RH to 85%RH was observed due to the changeable refractive index of the ZnO coating material which modified the light propagation at the output of the MLR. The result shows that the sensitivity of the proposed sensor increases by a factor of 2 as compared to the uncoated MLR. The output power of the ZnO coated MLR drops linearly from −29.3 dBm to −43 dBm when relative humidity increases from 35%RH to 85%RH. The linearity and resolution of the ZnO coated MLR also outperformed the uncoated MLR with 99.4% and 0.013%RH respectively

Agarose gel coated glass substrate for formaldehyde sensing application

This paper demonstrated an intensity modulation detection system employing agarose gel coated on the glass substrate for formaldehyde sensing application. The objectives of this work is to develop a simple and low cost formaldehyde sensor using commercially available microscope glass substrate, coating material and data acquisition unit. The glass substrate was coated with agarose gel using low temperature synthesis method which has superiority in term of high porosity and capable to absorb molecule around it. The formaldehyde detection is based on the change in refractive index (RI) of the agarose gel as a coating material. The RI change of the coating materials will modulate the output light intensity when the concentration level of the formaldehyde varies. This is due to the intensity of the light weakening by absorption and scattering when light propagated through the sensing material. A significant response to formaldehyde concentrations was observed with the output voltage reduced linearly from 1.1V to 0.4V. The sensitivity and the linearity of the proposed sensor improve by a factor of 1.02 and 1.03 respectively as compared to uncoated glass substrate. Moreover, it performs better in term of stability, hysteresis and time response. The proposed formaldehyde sensor avoid utilization of costly optical sensor setup based on laser source which are not feasible for large scale production. Based on the experiment results, the proposed sensor has a good potential as a formaldehyde sensor which is essential for food, health and environmental secto

ZnO nanorods coated tapered u-shape plastic optical fiber for relative humidity detection

A relative humidity sensor was fabricated by exploiting an evanescent wave (EW) on a U-bent tapered plastic optical fiber (POF) coated with zinc oxide (ZnO) nanorods. The POF was tapered manually using a polishing method to a diameter of 0.5 mm, a length of 5 cm, and a radius of 5 cm. ZnO nanorods were synthesized using a hydrothermal method and grown on the POF by a seeding process for 12 h. A significant response of the sensor was observed when the sensor was exposed to 35 to 90%RH due to the intense chemisorption process and changeable relative index in the POF. The sensitivity and resolution of the sensor have been improved by factors of 1.23 and 2.18, respectively, compared to the conventional tapered POF sensor without ZnO coating. Besides, the ZnO-coated sensor also exhibited better repeatability properties in terms of output voltage when exposed to 35 to 90%RH for three repeated measurements. The obtained results revealed that the proposed new POF sensor has an excellent sensing performance as an RH sensor in terms of sensitivity, repeatability, and stability propertie

Detection of acetone as a potential non-invasive diagnosis tool for diabetes patients

This work investigated the demonstration of acetone detection device as a potential tool to diagnose diabetes patients. It offers simple and low cost approach based on glass substrate platform. The glass substrate was coated with agarose gel as a sensitive material to increase the sensing response. It has superiority in term of high porosity and capable to absorb molecule around it. The sensing mechanism is based on the change in refractive index (RI) of the agarose gel coating layer when exposed to variation acetone concentration level. This is due to the intensity of the light weakening by absorption and scattering when light propagated through the sensing material. The proposed sensor produces a significant response towards acetone concentrations with the output voltage reduced linearly from 1.6V to 1.2V. The sensitivity and resolution of the agarose coated glass substrate improves by a factor of 1.08 and 1.14 respectively as compared to uncoated glass substrate. It also performed better in term of linearity, stability, response time and hysteresis. The non-involvement of costly laser source based instruments make the proposed sensor become more practical for large production while maintaining a good sensing performances. Based on the experiment results, the proposed acetone sensor has a persuasive potential as an early biomarker for diabetes diagnosis tool

Development of Acetone Liquid Concentration Detection Sensor by Using Fiber Optic for Diabetic Level Detection

The design of current fiber optic sensor technology especially when related to the chemical still requires a certain degree of the quantitative reliability. The acetone is one of chemical found in the bodily fluid for diabetic person and it would be obvious during fasting. The acetone level could be monitored which is indicate the severity of the diabetes. In this experiment, 4 samples of acetone are used with different concentrations between 20% until 80%. It is represented four different level of diabetic. Fiber optic would be dipped in every concentration before measuring process. Each concentration presented in different line graph and analyze for sensitivity value using statistical method. By using 1550nm wavelength of light source, the maximum sensitivity of 1.064 is obtained at second slope for 40% of concentration, respectively. This is showed that fiber optic sensor could be use as diabetic level sensor. However this sensor would be in high performance at 40% concentration of acetone

Corn Oil Concentrations Detection for Food Industry Research Development by Using Application of Fiber Optic Liquid Sensor Concept

This paper purposed application of fiber optic as liquid sensor for detection of various concentrations of corn oil. The final result would an additional understanding about fiber optic sensor and could be used in related field such as food industry sector. They are 20 samples of corn oil with different concentrations between 0% until 100% are tasted. For every concentration, would experience a dipped process together with fiber optic before measuring process. Each of concentrations would present different results in line graph. The experiment results would be discussed in listed values of sensitivity, correlation and coefficient of determination of graft which are totally dependent on concentration of corn oil and the light source. With a different value of concentration and 1550nm wavelength of light source, the maximum sensitivity of 0.00072 the coefficient of determination 94.0% is obtained at third slope, respectively. Fiber optic is successfully to be corn oil liquid sensor and would be in high performance by using 1550 nm wavelength of light source and measuring concentration more than 85%

Development of Acetone Liquid Concentration Detection Sensor by Using Fiber Optic for Diabetic Level Detection

The design of current fiber optic sensor technology especially when related to the chemical still requires a certain degree of the quantitative reliability. The acetone is one of chemical found in the bodily fluid for diabetic person and it would be obvious during fasting. The acetone level could be monitored which is indicate the severity of the diabetes. In this experiment, 4 samples of acetone are used with different concentrations between 20% until 80%. It is represented four different level of diabetic. Fiber optic would be dipped in every concentration before measuring process. Each concentration presented in different line graph and analyze for sensitivity value using statistical method. By using 1550nm wavelength of light source, the maximum sensitivity of 1.064 is obtained at second slope for 40% of concentration, respectively. This is showed that fiber optic sensor could be use as diabetic level sensor. However this sensor would be in high performance at 40% concentration of acetone

Corn Oil Concentrations Detection for Food Industry Research Development by Using Application of Fiber Optic Liquid Sensor Concept

This paper purposed application of fiber optic as liquid sensor for detection of various concentrations of corn oil. The final result would an additional understanding about fiber optic sensor and could be used in related field such as food industry sector. They are 20 samples of corn oil with different concentrations between 0% until 100% are tasted. For every concentration, would experience a dipped process together with fiber optic before measuring process. Each of concentrations would present different results in line graph. The experiment results would be discussed in listed values of sensitivity, correlation and coefficient of determination of graft which are totally dependent on concentration of corn oil and the light source. With a different value of concentration and 1550nm wavelength of light source, the maximum sensitivity of 0.00072 the coefficient of determination 94.0% is obtained at third slope, respectively. Fiber optic is successfully to be corn oil liquid sensor and would be in high performance by using 1550 nm wavelength of light source and measuring concentration more than 85%