Halochromic optical nose for assessment of spoilage of packed seer fish (II): leaching resistance, correlation between halochromism and volatile amines

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kesavan Devarayan ◽  
Padmavathi P. ◽  
Kopperundevi Sivakami Nagaraju
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Real Time ◽  
Total Volatile ◽  
Real Time Monitoring ◽  
Content Type ◽  
Color Changes ◽  
Thin Film Sensors ◽  
Ft Ir ◽  
Volatile Amines

Purpose Development of thin film sensors with pH function for noninvasive real-time monitoring of spoilage of packed seafood such as fish, crab and shrimp are described in this study. It is also the purpose of this study to enhance the leaching resistance of the sensors by using a suitable strategy and to quantitatively correlate the sensor’s halochromism with the total volatile amine. Design/methodology/approach To prepare halochromic sensors with better leaching resistance, biocompatible materials such as starch, agar, polyvinyl alcohol and cellulose acetate along with a halochromic dye were used to prepare the thin film sensors. These thin films were evaluated for monitoring the spoilage of packed seafood at room temperature, 4°C and −2°C up to 30 days. The halochromic sensors were characterized using UV-visible and FT-IR spectroscopy. Findings CIELab analyses of the halochromism of the thin film sensors revealed that the color changes exhibited by the sensors in response to the spoilage of seafood are visually distinguishable. Further, the halochromic response of the thin films was directly proportional to the amount of total volatile base nitrogen that evolved from the packed seafood. Excellent leaching resistance was observed for the developed thin film sensors. The halochromic property of the sensors is reversible and thus the sensors are recyclable. Besides, the thin film sensors exhibited significant biodegradability. Originality/value This study provides insights for use of different biocompatible polymers for obtaining enhanced leaching resistance in halochromic sensors. Further, the color changes exhibited by the sensors are in line with the total volatile amines evolved from the packed seafood. These results highlight the importance of the developed halochromic thin film sensors for real-time monitoring of the spoilage of packed seafood.

Halochromic optical nose for assessment of spoilage of packed seer fish

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kesavan Devarayan ◽  
Kopperundevi Sivakami Nagaraju ◽  
Padmavathi Pandiyan
Keyword(s):  
Thin Film ◽  
Real Time ◽  
Design Methodology ◽  
Real Time Monitoring ◽  
Content Type ◽  
Color Changes ◽  
Thin Film Sensors ◽  
Unique Color ◽  
Indicator Dyes ◽  
Seer Fish

Purpose The present study aims to describe the development of halochromic thin film sensors using mixed indicator dyes for monitoring the spoilage of packed seer fish. Design/methodology/approach Thin film was prepared using renewable polysaccharide incorporated with mixed indicator dyes. The thin film was characterized using ultraviolet visible and Fourier transform-infrared spectroscopy. The characteristics of the thin film were studied by analyzing the CIELAB and Red Green Blue values and biodegradability. The thin films were evaluated for real-time monitoring of the spoilage of packed seer fish. Findings The thin film sensors were found to exhibit excellent halochromism. The color changes were visible and distinguishable. The sensors responded efficiently for real-time monitoring of spoilage of fish by showing unique color changes. Originality/value This study provides promising mixed indicator that exhibits different colors in the alkaline pH. Also the present study reveals a potential combination of materials for preparation of halochromic sensors that can be used for monitoring the spoilage of packed seer fish in real time.

Insert-mounted thin film sensors for real-time monitoring of tool conditions

1988 ◽  
Vol 166 ◽  
pp. 387-395 ◽  
Author(s):  
W.P. Robbins ◽  
B. Bischoff ◽  
S. Ramalingen
Keyword(s):  
Thin Film ◽  
Real Time ◽  
Real Time Monitoring ◽  
Thin Film Sensors

scholarly journals A review on thin films, conducting polymers as sensor devices

2022 ◽  
Author(s):  
E.L. Veera Prabakaran ◽  
K Senthil Vadivu ◽  
B Mouli Prasanth
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Environmental Conditions ◽  
Future Research ◽  
Physical Parameters ◽  
Research Needs ◽  
Future Perspectives ◽  
Thin Film Technology ◽  
Thin Film Sensors ◽  
Sensor Devices

Abstract Thin film sensors are used to monitor environmental conditions by measuring the physical parameters. By using thin film technology, the sensors are capable of conducting precise measurements. Moreover, the measurements are stable and dependable. Furthermore, inexpensive sensor devices can be produced. In this paper, thin film technology for the design and fabrication of sensors that are used in various applications is reviewed. Further, the applications of thin film sensors in the fields of biomedical, energy harvesting, optical, and corrosion applications are also presented. From the review, the future research needs and future perspectives are identified and discussed.

High-Resolution Quadrature Photopyroelectric Spectroscopy of a-Si:H Thin Films Deposited on Silicon Wafers

1995 ◽  
Vol 49 (6) ◽  
pp. 819-824 ◽  
Author(s):  
Jun Shen ◽  
Andreas Mandelis ◽  
Andreas Othonos ◽  
Joseph Vanniasinkam
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Wave ◽  
Incident Radiation ◽  
Surface Films ◽  
Si Substrates ◽  
Wafer Substrate ◽  
Ir Transmission ◽  
Ft Ir ◽  
Lock In

The recently developed photothermal technique of quadrature photopyroelectric spectroscopy (Q-PPES) has been applied to measurements of amorphous Si thin films deposited on crystalline Si substrates. Direct, meaningful comparisons have been made between purely optical transmission in-phase (IP-PPES) spectra, and purely thermal-wave sub-gap spectra with the use of a novel noncontacting PPES instrument to record lock-in in-phase and quadrature spectra, respectively. FT-IR transmission spectra have also been obtained for a comparison with this IP-PPES optical method. The results of the present work showed that the FT-IR method performs the worst in terms of spectral resolution of thin films and sub-bandgap defect/impurity absorptions inherent in the Si wafer substrate. The optical IP-PPES channel, however, albeit more sensitive than the FT-IR technique, fails to resolve spectra from surface films thinner than 2100 Å, but is sensitive to sub-bandgap absorptions. The thermal-wave Q-PPES channel is capable of resolving thin-film spectra well below 500 Å thick and exhibits strong signal levels from the crystalline Si sub-bandgap absorptions. Depending on the surface thin-film orientation toward, or away from, the direction of the incident radiation, the estimated minimum mean film thickness resolvable spectroscopically by Q-PPES is either 40 Å or 100 Å, respectively.

Real-time monitoring of trap dynamics reveals the electronic states that limit charge transport in crystalline organic semiconductors

2020 ◽  
Vol 7 (9) ◽  
pp. 2390-2398
Author(s):  
Hamna F. Iqbal ◽  
Emma K. Holland ◽  
John E. Anthony ◽  
Oana D. Jurchescu
Keyword(s):  
Thin Film ◽  
Charge Transport ◽  
Real Time ◽  
Organic Semiconductors ◽  
Thin Film Transistors ◽  
Electronic States ◽  
Organic Thin Film Transistors ◽  
Organic Thin Film ◽  
Real Time Monitoring

Access to the dynamics of trap annihilation/generation resulting from isomer rearrangement identifies the performance-limiting processes in organic thin-film transistors.

Tribology of Ge thin films on stainless steel

2017 ◽  
Vol 69 (2) ◽  
pp. 182-189
Author(s):  
Lubomir Krabac ◽  
Vladimir Pejaković ◽  
Vladislav Drinek ◽  
Nicole Dörr ◽  
Ewald Badisch
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Stainless Steel ◽  
Design Methodology ◽  
Friction And Wear ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Chemical Vapor Deposition Method ◽  
Content Type ◽  
Sliding Distance

Purpose The purpose of this paper is to study the friction and wear behavior of germanium (Ge) thin films deposited by low-pressure chemical vapor deposition method on a chromium (Cr)-nickel (Ni) stainless steel substrate after being exposed to relatively mild sliding conditions (low loads and sliding distances). Design/methodology/approach Wear and friction experiments were conducted with a 100Cr6 steel ball sliding against flat Ge thin-film-coated stainless steel sheets (ball-on-flat microtribometer, no lubricant, normal loads of 50-100 mN, initial Hertzian contact pressures of 385-485 MPa, total sliding distance up to 200 mm and room temperature). Findings Scanning electron microscopy results revealed that prepared Ge thin films consisted of two different morphologies: curved nanowires and cone-shaped nano-/microdroplets. Regarding friction and wear characteristics of the investigated samples, the substrates coated with Ge thin films did not affect the coefficient of friction significantly by load. The wear of the base material (Cr-Ni stainless steel) was not observed under the mentioned experimental conditions (see the “Design/methodology/approach” section); however, with increased sliding distance and/or applied load, a rupture of the Ge film and an exposure of the stainless steel substrate to the 100Cr6 ball can be expected. Furthermore, the observations suggest that the smearing of Ge nano- and microstructures, plastically deformed during tribotesting, over the surface exposed to the sliding contact is the dominant tribological process. Originality/value For the first time, the tribological interaction between Ge thin film and steel surface was investigated under dry sliding conditions using a ball-on-flat microtribometer, and the obtained results provide a useful base for the further research on tribology of Ge-based thin films.

Real-time monitoring of excimer laser ablation of multilayer thin films by detecting acoustic emission

2002 ◽  
Author(s):  
Guangyu Liu ◽  
Erol C. Harvey ◽  
Dario J. Toncich ◽  
Jason P. Hayes ◽  
Choon K. Ng ◽  
...  
Keyword(s):  
Thin Films ◽  
Acoustic Emission ◽  
Laser Ablation ◽  
Real Time ◽  
Excimer Laser ◽  
Multilayer Thin Films ◽  
Real Time Monitoring ◽  
Excimer Laser Ablation

Non-Contact Real-Time Evaluation of Polyimide Thin Film Thermoelastic Properties Through Impulsive Stimulated Thermal Scattering

1992 ◽  
Vol 284 ◽  
Author(s):  
J. A. Rogers ◽  
A. R. Duggal ◽  
K. A. Nelson
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Real Time ◽  
Viscoelastic Properties ◽  
Thermoelastic Properties ◽  
Substrate Adhesion ◽  
Thermal Scattering ◽  
Film Substrate ◽  
Time Evaluation

ABSTRACTWe demonstrate a new purely optical based method for the excitation and detection of acoustic and thermal disturbances in thin films. This technique is applied to the determination of the viscoelastic properties of unsupported and silicon supported polyimide thin (∼1 micron) films. We show how this technique can be used to detect film delaminations and suggest how it may be used to probe film-substrate adhesion quality.

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