Laser-Matter Interaction for Nanostructuration and Characterization: From Fundamentals to Sensing and Energy Applications

A special issue of Nanomaterials (ISSN 2079-4991). This special issue belongs to the section "Nanofabrication and Nanomanufacturing".

Deadline for manuscript submissions: closed (15 March 2024) | Viewed by 27088

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Department of Physics and Astronomy “Ettore Majorana”, University of Catania, Via Santa Sofia 64, 95123 Catania, Italy
Interests: nanofabrication; nano-electrochemical sensors; electroanalysis; X-ray photoelectron spectroscopy
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Guest Editor

E-Mail Website
Guest Editor
Department of Physics and Astronomy “Ettore Majorana”, University of Catania, 95123 Catania, Italy
Interests: deposition techniques; thin films; advanced materials; characterization techniques; nanostructures; electrocatalysts; water splitting
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Today, nanomaterials represent one of the most important topics of 21st-century scientific and technological research. Thus, recent years have seen the exploitation of the nanomaterials potentialities in all the technological fields connected to human society challenges. In fact, nanomaterials having at least one dimension in the nanometer-scale present significant unconventional physical and chemical properties with respect to corresponding bulk materials. An example of nanomaterials includes 1D materials such as single and multiwalled nanotubes, metals and oxide nanowires, 2D materials such as graphene and newly emergent 2D nanomaterials such as Xenes (e.g., borophene, silicene, germanene, stanene, phosphorene, arsenene, antimonene, bismuthene, and tellurene), conductive fibers, 3D nanostructures such as multimetal nanoparticles, carbon–metal nanostructures, and sensing surfaces including a variety of hierarchically combinations of these materials, providing synergistic effects. However, the effective success of nanomaterials in device design and production is strictly dependent on the development of low-cost, versatile, simple, and high-throughput nanofabrication and nanopatterning approaches. Over the last few years, among the various fabrication methods, laser technology for nanoscale material synthesis and processing has seen an enormous development. In fact, the use of lasers has opened up new possibilities for material nanoprocessing because of a wide variety of nanostructures which can be obtained due to laser–matter interaction phenomena and controlling the laser process parameters. In addition, laser-based nanofabrication approaches can take advantage of local processing down to the micrometer and even sub-micrometer range, minimized thermal damage to the substrate and neighboring regions, non-contact nature, non-planar processing, and the possibility to combine it with other types of processing steps. Furthermore, nanomaterial development was accompanied by nanodevice fabrication, including, at present, the most investigated organic electronics devices, optical sensors, gas sensors, magnetic sensors, and non-enzymatic electrochemical biosensors.  

For this Special Issue, we invite researchers to submit original research articles, letters, as well as review and prospective view articles on laser-matter interaction for nanostructuration and characterization.

Dr. Antonino Scandurra
Dr. Francesco Ruffino
Dr. Sergio Battiato
Guest Editors

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Keywords

  • near-field-induced spatially-confined photochemical deposition
  • laser-assisted chemical vapor deposition (LCVD)
  • laser dewetting of metals
  • laser ablation
  • laser vaporization
  • pulsed laser deposition (PLD)
  • sensing and biosensing
  • plasmonics
  • energy (photovoltaics devices, thermoelectric devices, fuel cells, etc.)
  • catalysis and photocatalysis
  • micro- and nano-electronics
  • supercapacitors

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Published Papers (12 papers)

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Research

11 pages, 2499 KiB  
Article
Cascaded All-Fiber Gas Raman Laser Oscillator in Deuterium-Filled Hollow-Core Photonic Crystal Fibers
by Hao Li, Wenxi Pei, Xuanxi Li, Luohao Lei, Jing Shi, Zhiyue Zhou and Zefeng Wang
Nanomaterials 2024, 14(8), 661; https://doi.org/10.3390/nano14080661 - 11 Apr 2024
Cited by 1 | Viewed by 1019
Abstract
Hollow-core photonic crystal fibers (HC-PCFs) provide an ideal transmission medium and experimental platform for laser–matter interaction. Here, we report a cascaded all-fiber gas Raman laser based on deuterium (D2)-filled HC-PCFs. D2 is sealed into a gas cavity formed by a [...] Read more.
Hollow-core photonic crystal fibers (HC-PCFs) provide an ideal transmission medium and experimental platform for laser–matter interaction. Here, we report a cascaded all-fiber gas Raman laser based on deuterium (D2)-filled HC-PCFs. D2 is sealed into a gas cavity formed by a 49 m-long HC-PCF and solid-core fibers, and two homemade fiber Bragg gratings (FBGs) with the Raman and pump wavelength, respectively, are further introduced. When pumped by a pulsed fiber amplifier at 1540 nm, the pure rotational stimulated Raman scattering of D2 occurs inside the cavity. The first-order Raman laser at 1645 nm can be obtained, realizing a maximum power of ~0.8 W. An all-fiber cascaded gas Raman laser oscillator is achieved by adding another 1645 nm high-reflectivity FBG at the output end of the cavity, reducing the peak power of the cascaded Raman threshold by 11.4%. The maximum cascaded Raman power of ~0.5 W is obtained when the pump source is at its maximum, and the corresponding conversion efficiency inside the cavity is 21.4%, which is 1.8 times that of the previous configuration. Moreover, the characteristics of the second-order Raman lasers at 1695 nm and 1730 nm are also studied thoroughly. This work provides a significant method for realizing all-fiber cascaded gas Raman lasers, which is beneficial for expanding the output wavelength of fiber gas lasers with a good stability and compactivity. Full article
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20 pages, 9916 KiB  
Article
Commercial-Scale Modification of NdFeB Magnets under Laser-Assisted Conditions
by Natalia Radwan-Pragłowska, Julia Radwan-Pragłowska, Karol Łysiak, Tomasz Galek, Łukasz Janus and Dariusz Bogdał
Nanomaterials 2024, 14(5), 431; https://doi.org/10.3390/nano14050431 - 27 Feb 2024
Cited by 2 | Viewed by 1774
Abstract
Rare Earth elements (REE) such as NdFeB are commonly used to produce permanent magnets. Thanks to their superior properties, these materials are highly desirable for green energy applications such as wind power generators or electric cars. Currently, REEs are critical for the ongoing [...] Read more.
Rare Earth elements (REE) such as NdFeB are commonly used to produce permanent magnets. Thanks to their superior properties, these materials are highly desirable for green energy applications such as wind power generators or electric cars. Currently, REEs are critical for the ongoing development of eco-friendly solutions in different industrial branches. The emerging issue of REE depletion has led to a need for new methods to enable the life cycle elongation, resistance to wear, and external factors improvement of NdFeB magnets. This can be achieved by advanced, nanostructured coating formation of magnet surfaces to increase their functionality and protect from humidity, pressure, temperature, and other factors. The aim of the following research was to develop a new, scalable strategy for the modification of NdFeB magnets using laser-assisted technique, also known as Laser cladding. For this purpose, four different micropowders were used to modify commercial NdFeB samples. The products were investigated for their morphology, structure, chemical composition, and crystallography. Moreover, magnetic flux density was evaluated. Our results showed that laser cladding constitutes a promising strategy for REE-based permanent magnets modification and regeneration and may help to improve durability and resistance of NdFeB components. Full article
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13 pages, 5642 KiB  
Article
Laser Ablation of Silicon Nanoparticles and Their Use in Charge-Coupled Devices for UV Light Sensing via Wavelength-Shifting Properties
by Algirdas Lazauskas, Dovilė Gimžauskaitė, Mindaugas Ilickas, Liutauras Marcinauskas, Mindaugas Aikas, Brigita Abakevičienė and Dmytro Volyniuk
Nanomaterials 2023, 13(22), 2915; https://doi.org/10.3390/nano13222915 - 8 Nov 2023
Cited by 2 | Viewed by 2999
Abstract
This study explores the controlled laser ablation and corresponding properties of silicon nanoparticles (Si NP) with potential applications in ultraviolet (UV) light sensing. The size distribution of Si NPs was manipulated by adjusting the laser scanning speed during laser ablation of a silicon [...] Read more.
This study explores the controlled laser ablation and corresponding properties of silicon nanoparticles (Si NP) with potential applications in ultraviolet (UV) light sensing. The size distribution of Si NPs was manipulated by adjusting the laser scanning speed during laser ablation of a silicon target in a styrene solution. Characterization techniques, including transmission electron microscopy, Raman spectroscopy, and photoluminescence analysis, were employed to investigate the Si NP structural and photophysical properties. Si NP produced at a laser scanning speed of 3000 mm/s exhibited an average diameter of ~4 nm, polydispersity index of 0.811, and a hypsochromic shift in the Raman spectrum peak position. Under photoexcitation at 365 nm, these Si NPs emitted apparent white light, demonstrating their potential for optoelectronic applications. Photoluminescence analysis revealed biexponential decay behavior, suggesting multiple radiative recombination pathways within the nanoscale structure. Furthermore, a thin film containing Si NP was utilized as a passive filter for a 2nd generation CCD detector, expanding the functionality of the non-UV-sensitive detectors in optics, spectrometry, and sensor technologies. Full article
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9 pages, 3593 KiB  
Article
Integrating Fluorescent Nanodiamonds into Polymeric Microstructures Fabricated by Two-Photon Polymerization
by Filipe A. Couto, Marcelo B. Andrade, Adriano J. G. Otuka, Sebastião Pratavieira, Sergio R. Muniz and Cleber R. Mendonça
Nanomaterials 2023, 13(18), 2571; https://doi.org/10.3390/nano13182571 - 16 Sep 2023
Cited by 2 | Viewed by 2787
Abstract
Nitrogen-vacancy (NV) and other color centers in diamond have attracted much attention as non-photobleaching quantum emitters and quantum sensors. Since microfabrication in bulk diamonds is technically difficult, embedding nanodiamonds with color centers into designed structures is a way to integrate these quantum emitters [...] Read more.
Nitrogen-vacancy (NV) and other color centers in diamond have attracted much attention as non-photobleaching quantum emitters and quantum sensors. Since microfabrication in bulk diamonds is technically difficult, embedding nanodiamonds with color centers into designed structures is a way to integrate these quantum emitters into photonic devices. In this study, we demonstrate a method to incorporate fluorescent nanodiamonds into engineered microstructures using two-photon polymerization (2PP). We studied the optimal concentration of nanodiamonds in the photoresist to achieve structures with at least one fluorescent NV center and good structural and optical quality. Fluorescence and Raman spectroscopy measurements were used to confirm the presence and location of the nanodiamonds, while absorbance measurements assessed scattering losses at higher concentrations. Our results show the feasibility of fabricating microstructures embedded within fluorescent nanodiamonds via 2PP for photonics and quantum technology applications. Full article
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9 pages, 5379 KiB  
Communication
Generation of a Focused THz Vortex Beam from a Spintronic THz Emitter with a Helical Fresnel Zone Plate
by Xiaoqiang Zhang, Yong Xu, Bin Hong, Fan Zhang, Anting Wang and Weisheng Zhao
Nanomaterials 2023, 13(14), 2037; https://doi.org/10.3390/nano13142037 - 10 Jul 2023
Cited by 3 | Viewed by 1414
Abstract
Similar to optical vortex beams, terahertz (THz) vortex beams (TVBs) also carry orbital angular momentum (OAM). However, little research has been reported on the generation of TVBs. In this paper, based on the detour phase technique, we design a series of spintronic terahertz [...] Read more.
Similar to optical vortex beams, terahertz (THz) vortex beams (TVBs) also carry orbital angular momentum (OAM). However, little research has been reported on the generation of TVBs. In this paper, based on the detour phase technique, we design a series of spintronic terahertz emitters with a helical Fresnel zone plate (STE-HFZP) to directly generate focused TVBs with topological charges (TCs) of l = ±1, ±2 and ±3, respectively. The STE-HFZP is a hybrid THz device composed of a terahertz emitter and a THz lens, and it has a high numerical aperture (NA), achieving subwavelength focal spots. Its focus properties are surveyed systemically through accurate simulations. This STE-HFZP can also generate focused TVBs with higher order TCs. More importantly, the components of the focused electric field with OAM make up the majority of the intensity and have potential applications in the field of THz communications, THz imaging and atom trapping. Full article
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12 pages, 5734 KiB  
Article
Sub-Millisecond Laser-Irradiation-Mediated Surface Restructure Boosts the CO Production Yield of Cobalt Oxide Supported Pd Nanoparticles
by Praveen Kumar Saravanan, Dinesh Bhalothia, Guo-Heng Huang, Amisha Beniwal, Mingxing Cheng, Yu-Chieh Chao, Ming-Wei Lin, Po-Chun Chen and Tsan-Yao Chen
Nanomaterials 2023, 13(11), 1801; https://doi.org/10.3390/nano13111801 - 5 Jun 2023
Cited by 3 | Viewed by 1646
Abstract
The catalytic conversion of CO2 into valuable commodities has the potential to balance ongoing energy and environmental issues. To this end, the reverse water–gas shift (RWGS) reaction is a key process that converts CO2 into CO for various industrial processes. However, [...] Read more.
The catalytic conversion of CO2 into valuable commodities has the potential to balance ongoing energy and environmental issues. To this end, the reverse water–gas shift (RWGS) reaction is a key process that converts CO2 into CO for various industrial processes. However, the competitive CO2 methanation reaction severely limits the CO production yield; therefore, a highly CO-selective catalyst is needed. To address this issue, we have developed a bimetallic nanocatalyst comprising Pd nanoparticles on the cobalt oxide support (denoted as CoPd) via a wet chemical reduction method. Furthermore, the as-prepared CoPd nanocatalyst was exposed to sub-millisecond laser irradiation with per-pulse energies of 1 mJ (denoted as CoPd-1) and 10 mJ (denoted as CoPd-10) for a fixed duration of 10 s to optimize the catalytic activity and selectivity. For the optimum case, the CoPd-10 nanocatalyst exhibited the highest CO production yield of ∼1667 μmol g−1catalyst, with a CO selectivity of ∼88% at a temperature of 573 K, which is a 41% improvement over pristine CoPd (~976 μmol g−1catalyst). The in-depth analysis of structural characterizations along with gas chromatography (GC) and electrochemical analysis suggested that such a high catalytic activity and selectivity of the CoPd-10 nanocatalyst originated from the sub-millisecond laser-irradiation-assisted facile surface restructure of cobalt oxide supported Pd nanoparticles, where atomic CoOx species were observed in the defect sites of the Pd nanoparticles. Such an atomic manipulation led to the formation of heteroatomic reaction sites, where atomic CoOx species and adjacent Pd domains, respectively, promoted the CO2 activation and H2 splitting steps. In addition, the cobalt oxide support helped to donate electrons to Pd, thereby enhancing its ability of H2 splitting. These results provide a strong foundation to use sub-millisecond laser irradiation for catalytic applications. Full article
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22 pages, 6200 KiB  
Article
Ultra-Sensitive and Fast Humidity Sensors Based on Direct Laser-Scribed Graphene Oxide/Carbon Nanotubes Composites
by Ammar Al-Hamry, Tianqi Lu, Haoran Chen, Anurag Adiraju, Salem Nasraoui, Amina Brahem, Danica Bajuk-Bogdanović, Saddam Weheabby, Igor A. Pašti and Olfa Kanoun
Nanomaterials 2023, 13(9), 1473; https://doi.org/10.3390/nano13091473 - 26 Apr 2023
Cited by 11 | Viewed by 2820
Abstract
In this paper, the relative humidity sensor properties of graphene oxide (GO) and graphene oxide/multiwalled nanotubes (GO/MWNTs) composites have been investigated. Composite sensors were fabricated by direct laser scribing and characterized using UV-vis-NIR, Raman, Fourier transform infrared, and X-ray photoemission spectroscopies, electron scanning [...] Read more.
In this paper, the relative humidity sensor properties of graphene oxide (GO) and graphene oxide/multiwalled nanotubes (GO/MWNTs) composites have been investigated. Composite sensors were fabricated by direct laser scribing and characterized using UV-vis-NIR, Raman, Fourier transform infrared, and X-ray photoemission spectroscopies, electron scanning microscopy coupled with energy-dispersive X-ray analysis, and impedance spectroscopy (IS). These methods confirm the composite homogeneity and laser reduction of GO/MWNT with dominant GO characteristics, while ISresults analysis reveals the circuit model for rGO-GO-rGO structure and the effect of MWNT on the sensor properties. Although direct laser scribing of GO-based humidity sensor shows an outstanding response (|ΔZ|/|Z| up to 638,800%), a lack of stability and repeatability has been observed. GO/MWNT-based humidity sensors are more conductive than GO sensors and relatively less sensitive (|ΔZ|/|Z| = 163,000%). However, they are more stable in harsh humid conditions, repeatable, and reproducible even after several years of shelf-life. In addition, they have fast response/recovery times of 10.7 s and 9.3 s and an ultra-fast response time of 61 ms when abrupt humidification/dehumidification is applied by respiration. All carbon-based sensors’ overall properties confirm the advantage of introducing the GO/MWNT hybrid and laser direct writing to produce stable structures and sensors. Full article
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14 pages, 3769 KiB  
Article
Model of Chronoamperometric Response towards Glucose Sensing by Arrays of Gold Nanostructures Obtained by Laser, Thermal and Wet Processes
by Antonino Scandurra, Valentina Iacono, Stefano Boscarino, Silvia Scalese, Maria Grazia Grimaldi and Francesco Ruffino
Nanomaterials 2023, 13(7), 1163; https://doi.org/10.3390/nano13071163 - 24 Mar 2023
Cited by 2 | Viewed by 1834
Abstract
Non-enzymatic electrochemical glucose sensors are of great importance in biomedical applications, for the realization of portable diabetic testing kits and continuous glucose monitoring systems. Nanostructured materials show a number of advantages in the applications of analytical electrochemistry, compared to macroscopic electrodes, such as [...] Read more.
Non-enzymatic electrochemical glucose sensors are of great importance in biomedical applications, for the realization of portable diabetic testing kits and continuous glucose monitoring systems. Nanostructured materials show a number of advantages in the applications of analytical electrochemistry, compared to macroscopic electrodes, such as great sensitivity and little dependence on analyte diffusion close to the electrode–solution interface. Obtaining electrodes based on nanomaterials without using expensive lithographic techniques represents a great added value. In this paper, we modeled the chronoamperometric response towards glucose determination by four electrodes consisting of nanostructured gold onto graphene paper (GP). The nanostructures were obtained by electrochemical etch, thermal and laser processes of thin gold layer. We addressed experiments obtaining different size and shape of gold nanostructures. Electrodes have been characterized by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry, and chronoamperometry. We modeled the current-time response at the potential corresponding to two-electrons oxidation process of glucose by the different nanostructured gold systems. The finest nanostructures of 10–200 nm were obtained by laser dewetting of 17 nm thin and 300 °C thermal dewetting of 8 nm thin gold layers, and they show that semi-infinite linear diffusion mechanism predominates over radial diffusion. Electrochemical etching and 17 nm thin gold layer dewetted at 400 °C consist of larger gold islands up to 1 μm. In the latter case, the current-time curves can be fitted by a two-phase exponential decay function that relies on the mixed second-order formation of adsorbed glucose intermediate followed by its first-order decay to gluconolactone. Full article
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15 pages, 3367 KiB  
Article
Light Conversion upon Photoexcitation of NaBiF4:Yb3+/Ho3+/Ce3+ Nanocrystalline Particles
by Enrico Trave, Michele Back, Davide Pollon, Emmanuele Ambrosi and Leonardo Puppulin
Nanomaterials 2023, 13(4), 672; https://doi.org/10.3390/nano13040672 - 9 Feb 2023
Cited by 5 | Viewed by 2220
Abstract
NaBiF4 nanocrystalline particles were synthesized by means of a facile precipitation synthesis route to explore upconversion emission properties when doped with lanthanide ions. In particular, the incorporation of the Yb3+-Ho3+-Ce3+ triad with controlled ion concentration facilitates near-IR [...] Read more.
NaBiF4 nanocrystalline particles were synthesized by means of a facile precipitation synthesis route to explore upconversion emission properties when doped with lanthanide ions. In particular, the incorporation of the Yb3+-Ho3+-Ce3+ triad with controlled ion concentration facilitates near-IR pumping conversion into visible light, with the possibility of color emission tuning depending on Ce3+ doping amount. We observed that introducing a Ce3+ content up to 20 at.% in NaBiF4:Yb3+/Ho3+, the chromaticity progressively turns from green for the Ce3+ undoped system to red. This is due to cross-relaxation mechanisms between Ho3+ and Ce3+ ions that influence the relative efficiency of the overall upconversion pathways, as discussed on the basis of a theoretical rate equation model. Furthermore, experimental results suggest that the photoexcitation of intra-4f Ho3+ transitions with light near the UV-visible edge can promote downconverted Yb3+ near-IR emission through quantum cutting triggered by Ho3+-Yb3+ energy transfer mechanisms. The present study evidences the potentiality of the developed NaBiF4 particles for applications that exploit lanthanide-based light frequency conversion and multicolor emission tuning. Full article
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15 pages, 2729 KiB  
Article
Alkaline Electro-Sorption of Hydrogen Onto Nanoparticles of Pt, Pd, Pt80Pd20 and Cu(OH)2 Obtained by Pulsed Laser Ablation
by Antonino Scandurra, Valentina Iacono, Stefano Boscarino, Silvia Scalese, Maria Grazia Grimaldi and Francesco Ruffino
Nanomaterials 2023, 13(3), 561; https://doi.org/10.3390/nano13030561 - 30 Jan 2023
Cited by 2 | Viewed by 1911
Abstract
Recently, hydrogen evolution reaction (HER) in alkaline media has received a renewed interest both in the fundamental research as well as in practical applications. Pulsed Laser Ablation in Liquid (PLAL) has been demonstrated as a very useful technique for the unconventional preparation of [...] Read more.
Recently, hydrogen evolution reaction (HER) in alkaline media has received a renewed interest both in the fundamental research as well as in practical applications. Pulsed Laser Ablation in Liquid (PLAL) has been demonstrated as a very useful technique for the unconventional preparation of nanomaterials with amazing electro-catalyst properties toward HER, compared to those of nanomaterials prepared by conventional methods. In this paper, we compared the electro-sorption properties of hydrogen in alkaline media by Pt, Pd, Pt80Pd20, and Cu(OH)2 nanoparticles (NPs) prepared by PLAL. The NPs were placed onto graphene paper (GP). Noble metal particles have an almost spherical shape, whereas Cu(OH)2 presents a flower-bud-like shape, formed by very thin nanowalls. XPS analyses of Cu(OH)2 are compatible with a high co-ordination of Cu(II) centers by OH and H2O. A thin layer of perfluorosulfone ionomer placed onto the surface of nanoparticles (NPs) enhances their distribution on the surface of graphene paper (GP), thereby improving their electro-catalytic properties. The proposed mechanisms for hydrogen evolution reaction (HER) on noble metals and Cu(OH)2 are in line with the adsorption energies of H, OH, and H2O on the surfaces of Pt, Pd, and oxidized copper. A significant spillover mechanism was observed for the noble metals when supported by graphene paper. Cu(OH)2 prepared by PLAL shows a competitive efficiency toward HER that is attributed to its high hydrophilicity which, in turn, is due to the high co-ordination of Cu(II) centers in very thin Cu(OH)2 layers by OH- and H2O. We propose the formation of an intermediate complex with water which can reduce the barrier energy of water adsorption and dissociation. Full article
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11 pages, 2441 KiB  
Article
Tunable Optimal Dual Band Metamaterial Absorber for High Sensitivity THz Refractive Index Sensing
by Madurakavi Karthikeyan, Pradeep Jayabala, Sitharthan Ramachandran, Shanmuga Sundar Dhanabalan, Thamizharasan Sivanesan and Manimaran Ponnusamy
Nanomaterials 2022, 12(15), 2693; https://doi.org/10.3390/nano12152693 - 5 Aug 2022
Cited by 46 | Viewed by 2820
Abstract
We present a simple dual band absorber design and investigate it in the terahertz (THz) region. The proposed absorber works in dual operating bands at 5.1 THz and 11.7 THz. By adjusting the graphene chemical potential, the proposed absorber has the controllability of [...] Read more.
We present a simple dual band absorber design and investigate it in the terahertz (THz) region. The proposed absorber works in dual operating bands at 5.1 THz and 11.7 THz. By adjusting the graphene chemical potential, the proposed absorber has the controllability of the resonance frequency to have perfect absorption at various frequencies. The graphene surface plasmon resonance results in sharp and narrow resonance absorption peaks. For incident angles up to 8°, the structure possesses near-unity absorption. The proposed sensor absorber’s functionality is evaluated using sensing medium with various refractive indices. The proposed sensor is simulated for glucose detection and a maximum sensitivity of 4.72 THz/RIU is observed. It has a maximum figure of merit (FOM) and Quality factor (Q) value of 14 and 32.49, respectively. The proposed optimal absorber can be used to identify malaria virus and cancer cells in blood. Hence, the proposed plasmonic sensor is a serious contender for biomedical uses in the diagnosis of bacterial infections, cancer, malaria, and other diseases. Full article
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11 pages, 7641 KiB  
Article
Reconfigurable, Stretchable Strain Sensor with the Localized Controlling of Substrate Modulus by Two-Phase Liquid Metal Cells
by Linna Mao, Taisong Pan, Junxiong Guo, Yizhen Ke, Jia Zhu, Huanyu Cheng and Yuan Lin
Nanomaterials 2022, 12(5), 882; https://doi.org/10.3390/nano12050882 - 7 Mar 2022
Cited by 13 | Viewed by 2744
Abstract
Strain modulation based on the heterogeneous design of soft substrates is an effective method to improve the sensitivity of stretchable resistive strain sensors. In this study, a novel design for reconfigurable strain modulation in the soft substrate with two-phase liquid cells is proposed. [...] Read more.
Strain modulation based on the heterogeneous design of soft substrates is an effective method to improve the sensitivity of stretchable resistive strain sensors. In this study, a novel design for reconfigurable strain modulation in the soft substrate with two-phase liquid cells is proposed. The modulatory strain distribution induced by the reversible phase transition of the liquid metal provides reconfigurable strain sensing capabilities with multiple combinations of operating range and sensitivity. The effectiveness of our strategy is validated by theoretical simulations and experiments on a hybrid carbonous film-based resistive strain sensor. The strain sensor can be gradually switched between a highly sensitive one and a wide-range one by selectively controlling the phases of liquid metal in the cell array with a external heating source. The relative change of sensitivity and operating range reaches a maximum of 59% and 44%, respectively. This reversible heterogeneous design shows great potential to facilitate the fabrication of strain sensors and might play a promising role in the future applications of stretchable strain sensors. Full article
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