ISens-Chip

Results

Promotion of project results

From the analysis of the interaction of light with matter based on the Maxwell equations, it was found that under certain conditions, a wave of charge densities confined to the surface and propagating along the interface exists. In the 70s of the last centuries, Kretschmann proposed a method of generating these waves using a prism and totally attenuated reflection. The strong coupling of light with this wave occurs at a certain angle under plasmonic resonance (SPR) conditions, the value of which depends on the ambient environment which consists mainly of liquids. This led to the development of sensors and instruments with plasmonic resonance of very high sensitivity and led to the creation of photonic devices that are widely commercialized.
The goal of this project was to eliminate the prism and develop a planar SPR structure, which must be scalable allowing miniaturization and the integration of several sensors on the same glass lamella. This was achieved by using a thick transmission diffraction grating with which the light is efficiently coupled in the SPR structure. The operation of this diffraction grating was elaborated, the
results being contained in several patent applications.
The use of diffraction grating makes it possible to build portable, mobile and cheaper devices. The reflection of light under certain conditions in the exact opposite direction from which the light comes allows the integration of these sensors into fiber optic networks that can be incorporated into intelligent real-time and remote environmental monitoring systems.

RESULTS 2

The project’s research activities included advanced analytical studies resulting in innovative surface plasmon resonance (SPR) models and structures that were carried out in several publications, patents and experimental research.

The steps taken mainly include:

1. Elaboration of the RPS structure

The development of a planar structure with multilayer SPR chipset was achieved. Coupling of light into the plasmonic structure through a volume holographic network with refractive index modulation. To increase the diffraction effectiveness of light, the angle of incidence and diffraction are selected to ensure Bragg conditions. The thickness of the diffraction grating is set independently of the waveguide thickness so that the optical parameters can be optimized independently. The SPR chipset contains plasmonic waveguide for the purpose of achieving higher sensitivity of the sensor to the refractive index of the environment.

2. Sensor architecture

We investigated and followed how the SPR sensor can be combined with
complementary sensor techniques to improve data interpretation and optimize biosensor design. As a result of the research, the architecture of the SPR sensor was developed. The flow of the analyte under investigation flows through a cell in which channels are dug. The cell is connected by flexible tubes with the liquid for diagnostics. The cell is glued with adhesive to the SPR chipset which consists of several functional layers. The first layer is gold with a thickness of 40-50 nm deposited on a substrate. A fictionalized layer consisting of biologically active substances (enzymes, antibodies) is applied over the gold film for selective adsorption of the analyte. The application of a thin film consisting of amorphous calcogenic material with a high refractive index that acts as a waveguide makes it possible to manipulate the resonance angle, sensor sensitivity and depth of penetration of the evanescent field. On the other side of the substrate, a thin film of amorphous calcogenic compound (As 2 S 3 in this case) is deposited, in which a diffraction grating is inscribed by the holographic method. The diffraction grating is a thick volume grating those acts in the Bragg diffraction regime. This ensures a high beam diffraction efficiency of the sample laser in a single maximum. The diffraction grating, which replaces the prism in conventional schemes, ensures a flatness of the structure, which makes it much more technological in its realization and cheapens the cost of the devices

3. Making the demonstrator. This includes a few directions.

First of all, the Technology for obtaining films from amorphous chalcogenide compounds with parameters specific to the SPR structure was developed. By thermal evaporation in vacuum, thin films of amorphous As 2 S 3 were obtained a) films for the plasmonic chipset with thicknesses in the range of 450-1000 nm and b) films for the volume diffraction grating with a thickness of 8 μm. The technological book has been developed. The films obtained with the laboratory high vacuum installation have the appropriate optical properties for the realization of the SPR structure, are reproduced under the specified conditions and correspond to the TRL4 technological level.

Secondly, the technology of making diffraction gratings by the holographic method was developed. For holographic exposure, the film of amorphous calcogenic compound which, in our case, has the composition As 2 S 3 is illuminated by two mutually coherent laser beams and incidents on the surface of the film. The Bragg grating must be tilted with respect to the film normal to satisfy the SPR conditions. For As 2 S 3 films with thickness h=8 μm, the appropriate wavelength of the writing laser was 532 nm. The diffraction efficiency was calculated according to the model developed by Kogelnic. The calculation for the Klein parameter Q = 2πλT/(nd2) under the above conditions gives the value Q=12, which denotes that diffraction gratings are 3D volume. In the SPR structure the diffraction grating is a phase one, it works in the transmission and the alignment corresponded to the Bragg resonance conditions.

Assembling the demonstrator. For the experiments, a demonstrator was built containing a cell with SPR interaction, which in the cross-section of the periodic microfluidic plasmonic nanostructure has two channels through which the liquid containing the substance to be analyzed leaks. For sensor modeling, a cell with two channels was developed and made through which the flow of liquid flows. All components are mounted on a transparent plexiglass platform. At the top, two channels are dug with a milling cutter. In each channel are drilled holes for inlet and outlet nozzles 2 made of brass, outer diameter 2.0 mm.

4. Demonstration of sensor functionality.

From laboratory components and those obtained technologically, the assembly was carried out, the constituent parts were aligned and the functionality of the device was checked. The parameters obtained were included in a measurement report. By adjusting the angle, the coupling of the red light from the He-Ne laser with the plasmon-polaritonic plasmon wave was obtained. The structure has been adjusted to achieve minimal reflectance. The diffraction efficiency (32%) and the sensitivity of the sensor (5.5 degrees/RIU) to the change of the refractive index of the liquid were experimentally determined. The results can be found in a demonstrator test report.

5. Publication and dissemination of results.

During the project period, 17 articles were published (with the necessary thanks to the project) in Web of Science; 16 articles in other databases; 2
chapters of books in international publishing houses; 32 participations in conferences; 6 national patent applications and 1 international patent application. Those listed denote the far exceeding of the indicators assumed in the financing application.

6. Estimated impact.

The results listed in pp. 1-4 denote that the results mounted in the project have been fulfilled. The results obtained in the research project contributed to the development of the interaction of light with matter in optical resonance structures. A new way of making plasmonic optical sensors using diffraction grating coupling separated from metal film has been established. Due to this, the network does not diminish the resonance characteristics, paving the way for optical performant plasmonic sensors. The main result consists in the development of a planar plasmonic optical sensor design that allows the scalability of several sensors on the same platform and the development of networks of sensors coupled with optical fibers. An invention for the SPR planar structure with embossed diffraction grating was proposed, filed for international patenting

RESULTS 3

17 Articles in Web of Science:

  1. M. Rusu, D. Savastru, V. Savu, Al. Stanciu, M. Tautan – Smart composite material microphone using a grating fiber optic sensor – aceptată la publicare în U.P.B. Sci. Bull., Series A, Vol. 86, Iss. 4, 2024
  2. M. Tautan, M. Zoran, R. Radvan, D. Savastru, D. Tenciu, Al. Stanciu – The Effects of Air Quality and the Impact of Climate Conditions on the First COVID-19 Wave in Wuhan and Four European Metropolitan Regions- Atmosphere, 2024, vol.15, iss. 10, art.1230, IDS No.: K5C0W
  3. A. Popescu, D. Savastru, Al. Stanciu – Improving the performance of surface plasmon resonance sensors for liquid chemical detection – Journal of Optoelectronics and Advanced Materials, Vol. 26, No. 7-8, July – August 2024, pp. 264 – 268, IDS No.: E5R6I
  4. D. Savastru, V. Savu, M. Rusu, M. Tautan, Al. Stanciu – Analysis of a high-power laser thermal phenomena induced onto a composite made uav/drone in flight- Journal of Optoelectronics and Advanced Materials, Vol. 26, No. 7-8, July – August 2024, pp. 316 – 326, IDS No.: E5R6I
  5. D. Savastru, M. Tautan, V. Savu, Al. Stanciu, M. Rusu – Grating optic fiber sensors detection of smart polymer composite delamination – U.P.B. Sci. Bull., Series A, Vol. 86, Iss. 3, 2024, pp.:145-156, ISSN 1223-7027, IDS No.: E2J1B
  6. M. Zoran, R. Radvan, D. Savastru, M. Tautan – Urban Air Pollution Exposure Impact on COVID-19 Transmission in Few Metropolitan Regions – Sustainability, Vol.: 16, Iss.: 14, Art. No.: 6119, 2024, https://doi.org/10.3390/su16146119, IDS No.: ZS3E9
  7. S. Dontu, C. Popa, D. Savastru, E. Carstea – Optical properties of riverine dissolved organic matter and influence of precipitation – a case study – Optoelectronics and Advanced Materials Rapid Communications, Vol. 18, ISS. 3-4/2024, pp.169-177, IDS No.: SR8Y4
  8. Aurelian Popescu, Dan Savastru, Mihai Stafe and Nicolae Puscas, Four-Layer Surface Plasmon Resonance Structures with Amorphous As2S3 Chalcogenide Films: A Review. Materials 2023, 16, 6110. https://doi.org/10.3390/ma16186110 – ISI, IF=3.4, Q2
  9. M. Iovu, I. Culeac, V. Verlan , Olga Bordian, M. Enachescu, A. A. Popescu, D.  Savastru, A. Lazar. Synthesis and optical properties of the glassy compound As 0.63 S 2.70 Sb 1.37 Te 0.30, Chalcogenide Letters, Vol. 20, No. 5, May 2023, p. 387 – 392. – ISI, IF=1.0, Q4
  10. Dan Savastru, L. Baschir, S. Miclos, R. Savastru, I. I. Lancranjan, Smart composite using fibre optic sensors for fluid flow characterization and temperature measurement, Composite Structures, vol. 304, part 1, 15 January 2023, art.nr. 116382
  11. R. Savastru, Dan Savastru, L. Baschir, S. Miclos, I. I. Lancranjan, Long period grating fibre sensor for detection of impurities infesting smart polymer composites, Composite Structures, vol. 312, 15 May 2023, art.nr. 116877
  12. Cristina L. Popa, Simona I. Dontu, Elfrida M. Carstea, Ioan-Cristian Ioja, Larisa I. Florescu, Alina C. Dumitrache, Gabriel Vanau, Ana-Maria Popa, Mirela Moldoveanu Land use impact on the levels of fluorescent dissolved organic matter, phytoplankton and zooplankton in urban lakes, Elsevier – Limnologica, vol. 99 (2023) art. nr. 126062;
  13. Zoran Maria, Savastru Roxana,  Savastru Dan, Tautan Marina, Peculiar weather patterns effects on air pollution and COVID-19 spread in Tokyo metropolis, Environmental Research, vol.228 (2023) art. nr. 115907.
  14. Maria A. Zoran; Roxana S. Savastru; Dan M. Savastru; Marina N. Tautan; Daniel V. Tenciu “Linkage between Airborne Particulate Matter and viral pandemic COVID-19 in Bucharest”,MDPI, Microorganisms, 2023, 11(10), 2531; https://doi.org/10.3390/microorganisms11102531
  15. M. Iovu, V. Verlan, O. Bordian, M. Enachescu, A. Popescu, Dan Savastru, L.B. Enache, S. Rosoiu, M. Bardeanu, O. A. Lazar, G. Mihai – Synthesis of glassy composite As0.63S2.70Sb1.37Te0.30 and its physical properties, Optoelectronics and Advanced Materials – Rapid Communications, Vol. 16, No. 11-12, Nov.-Dec., 2022, (Q4)
  16. M. Zoran, Roxana Savastru, Dan Savastru, M. Tautan – Cumulative effects of air pollution and climate drivers on COVID-19 multiwaves in Bucharest, Romania – Process Safety and Environmental Protection, Vol. 166, October 2022, Pp. 368-383, doi: 10.1016/j.psep.2022.08.042, (Q1)
  17. M. A. Calin, D. Manea, Roxana Savastru, S.V. Parasca – Mapping the distribution of melanin concentration in different Fitzpatrick skin types using hyperspectral imaging technique –in Photochemistry and Photobiology la data de 19 September 2022, doi: 10.1111/php.13725, (Q2)

16 Articles in other databases:

  1. M. Zoran, R. Radvan, D. Savastru, M. Tautan, A. Penache – Urban Green Space and Albedo Impacts on Surface Temperature in Bucharest Metropolitan Area – Proceedings Volume 13212, Tenth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2024); 132120A (2024) https://doi.org/10.1117/12.3034999
  2. M. Tautan, M. Zoran, R. Radvan, D. Savastru, D. Tenciu – Time series satellite data for assessment of drought impacts on vegetation land cover in dryland Constanta County, Romania – Proceedings Volume 13212, Tenth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2024); 132120D (2024) https://doi.org/10.1117/12.3035312
  3. M. Tautan, M. Zoran, R. Radvan, D. Savastru, A. Stanciu – Seismic Surveillance of Vrancea Active Region in Romania by Time Series Satellite Data Anomalies -Proceedings Volume 13212, Tenth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2024); 132120B (2024) https://doi.org/10.1117/12.3035001
  4. M. Zoran, R. Radvan, D. Savastru, M. Tautan, A. Stanciu – Linking urbanization with air pollution and thermal environment in Bucharest city – Proceedings Volume 13212, Tenth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2024); 1321209 (2024) https://doi.org/10.1117/12.3034998
  5. S. Dontu, C.L. Popa, E.M. Carstea, D. Savastru – Estimation of microplastics emitted by Bucharest households in wastewater treatment plants – Macromolecular Symposia, Vol. 413, Iss. 3, 2024, 2300149, pp: 1-3, https://doi.org/10.1002/masy.202300149,
  6. E. M. Carstea, C.L. Popa, S.I. Dontu, D. Savastru – Release of fluorescent organic matter by polystyrene in aquatic systems – Macromolecular Symposia, Vol. 413, Iss. 3, 2024, 2300150, pp:1-4, https://doi.org/10.1002/masy.202300150
  7. C. L. Popa, S. I. Dontu, E. M. Carstea, D. Savastru – Potential discharge of microplastics in surface runoff – Bucharest case study – Macromolecular Symposia, Vol. 413, Iss. 3, 2024, 2300152, pp:1-3, https://doi.org/10.1002/masy.202300152
  8. M. Zoran, R. Savastru, D. Savastru, M. Tautan, A. Penache “Spatiotemporal Changes of Urban Land Surface Albedo Impact on Thermal Environment in Bucharest Metropolitan City”, WSEAS Transactions on Environment and Development, pp.: 1037-1044, Vol. 19, 2023, DOI: 10.37394/232015.2023.19.98, E-ISSN: 2224-3496,
  9. D. Savastru, M. Zoran, R. Savastru, M. Tautan “Effects of climate change and urbanization on vegetation phenology in Bucharest metropolitan area”, WSEAS Transactions on Environment and Development, pp.: 961-968, Vol. 19, 2023, DOI: 10.37394/232015.2023.19.90, E-ISSN: 2224-3496,
  10. M. Zoran, R. Savastru, D. Savastru, M. Tautan, “Thermal infrared anomalies associated with recent crustal earthquakes in Gorj County in Romania”, WSEAS Transactions on Environment and Development, pp.: 873-880, Vol. 19, 2023, DOI: 10.37394/232015.2023.19.83, E-ISSN: 2224-3496,
  11. M. Zoran, R. Savastru, D. Savastru, M. Tautan, A. Penache, “Exploring with time-series satellite data of multiple stressors effects on urban/periurban vegetation”, Proceedings SPIE Vol. 12786, Ninth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2023); 127861E (2023) https://doi.org/10.1117/12.2680577, 21 September 2023,
  12. Dan Savastru, M. Zoran, R. Savastru, M. Tautan, D. Tenciu, “Time-series satellite data for assessment of Bucharest city thermal environment”, Proceedings SPIE Vol. 12786, Ninth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2023); 127861F (2023) https://doi.org/ 10.1117/12.2680592, 21 September 2023,
  13. D. Savastru, M. Zoran, R. Savastru, M. Tautan, D. Tenciu, “Association of air pollution and synoptic weather impacts on COVID-19 transmission through in-situ and geospatial data”, Proceedings SPIE Vol. 12786, Ninth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2023); 127860Q (2023) https://doi.org/10.1117/12.2680601, 21 September 2023,
  14. M. Zoran, R. Savastru, D. Savastru, M. Tautan, A. Penache, “Assessment of climate and anthropogenic impacts on the urban forest through derived MODIS satellite biophysical variables”, Proceedings SPIE Vol. 12786, Ninth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2023); 127861D (2023) https://doi.org/10.1117/12.2680584, 21 September 2023
  15. M.I. Rusu, V. Savu, D. Savastru, C.H. Gândescu, A. Stan, D.M. Cotorobai, “Sampling the travel distance of a vehicle through an unconventional method for data acquisition”, Journal of Optoelectronics and Advanced Materials vol.25, iss. 11-12, p. 563-571, November-December (2023)
  16. C.L. Popa, I.S. Dontu, I.C. Ioja, G.O. Vanau, A.M. Popa, C.H. Gandescu, A. Stan, D.M. Cotorobai, D. Savastru, E.M. Carstea, Preliminary water quality characterization of urban lakes using a state of the art optoelectronic technique, Journal of Optoelectronics and Advanced Materials, Vol. 25, Issue 11-12.

2 chapters of books in international publishing houses:

  1. Aurelian Popescu, Dan Savastru, Mihai Stafe and Nicolae Puscas, „Surface Plasmon Resonance (SPR) Structures Containing Amorphous Chalcogenide (ChG) Films as Plasmonic Waveguides: A Review”. In the book: Chemical and Materials Sciences – Developments and Innovations Vol. 1. B P International May 2024. Ed. By Prof. Akmal S. Gaballa. ISBN 978-81-973316-9-5 (Print) ISBN 978-81-973316-0-2 (eBook) DOI: https://doi.org/10.9734/bpi/cmsdi/v1/11917F
  2. Aurelian Popescu, Dan Savastru, Mihai Stafe, Nicolae Puscas, Four-Layer Surface Plasmon Resonance Structures with Amorphous As2S3 Chalcogenide Films: A Review. Published in: Prime Archives in Material Science: 5th Edition. Hyderabad, India: Vide Leaf. 2023

6 national patent applications:

  1. Nr. A/00401 din 09.07.2024 “Structură planară cu rezonanță plasmonică de suprafață cu rețea de difracție în volum” autori: A. A. Popescu, D. Savastru
  2. Nr. A/00706 din 15.11.2024 “Structură planară cu rezonanță plasmonică de suprafață având o rețea de difracție în relief și procedeu de realizare a acestei structuri” autori: A. A. Popescu, D. Savastru
  3. Nr. A/00647/31.10.2023, cu titlul: Sistem de sincronizare a semnalelor multiplexate transmise unidirecțional între două unități printr-un cablu ecranat monofilar, autori: Savu Valeriu, Rusu Mădălin Ion, Savastru Dan, Manea Dragoș.
  4. Nr. A/00741/21.11.2023, cu titlul: Dispozitiv de detectare a împămîntării prizelor rețelelor electrice monofazate pentru uzul casnic, autori: Rusu Mădălin Ion, Savu Valeriu
  5. Nr. A00202/2022, cu titlul “Mediu cu rezonanta plasmonica de suprafață pentru scrierea/ștergerea informației optice”, autori: Popescu A., Micloș S., Savu V., Vasile Georgiana, Neguțu C., Pușcaș N
  6. Nr. A/00273/2022 ”Amplificator controlat de nivelul semnalului de intrare pentru un detector Cherenkov în mediu salin”, V. Savu, M.I. Rusu, D. Savastru

1 international patent application:

  1. Nr. EP24020332.3 din 19.11.2024 “Structură planară cu rezonanță plasmonică de suprafață având o rețea de difracție in relief și procedeu de realizare a acestei structuri” autori: A. A. Popescu, D. Savastru