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Prof. Giedrius Janusas
Department of Mechanical Engineering, Kaunas University of Technology, Kaunas, Lithuania

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Journal article
Published: 30 May 2021 in Materials
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Taking into account X-ray diffraction, one of the well-known methods for calculating the stress-strain of crystals is Williamson-Hall (W–H). The W-H method has three models, namely (1) Uniform deformation model (UDM); (2) Uniform stress deformation model (USDM); and (3) Uniform deformation energy density model (UDEDM). The USDM and UDEDM models are directly related to the modulus of elasticity (E). Young’s modulus is a key parameter in engineering design and materials development. Young’s modulus is considered in USDM and UDEDM models, but in all previous studies, researchers used the average values of Young’s modulus or they calculated Young’s modulus only for a sharp peak of an XRD pattern or they extracted Young’s modulus from the literature. Therefore, these values are not representative of all peaks derived from X-ray diffraction; as a result, these values are not estimated with high accuracy. Nevertheless, in the current study, the W-H method is used considering the all diffracted planes of the unit cell and super cells (2 × 2 × 2) of Hydroxyapatite (HA), and a new method with the high accuracy of the W-H method in the USDM model is presented to calculate stress (σ) and strain (ε). The accounting for the planar density of atoms is the novelty of this work. Furthermore, the ultrasonic pulse-echo test is performed for the validation of the novelty assumptions.

ACS Style

Marzieh Rabiei; Arvydas Palevicius; Amir Dashti; Sohrab Nasiri; Ahmad Monshi; Akram Doustmohammadi; Andrius Vilkauskas; Giedrius Janusas. X-ray Diffraction Analysis and Williamson-Hall Method in USDM Model for Estimating More Accurate Values of Stress-Strain of Unit Cell and Super Cells (2 × 2 × 2) of Hydroxyapatite, Confirmed by Ultrasonic Pulse-Echo Test. Materials 2021, 14, 2949 .

AMA Style

Marzieh Rabiei, Arvydas Palevicius, Amir Dashti, Sohrab Nasiri, Ahmad Monshi, Akram Doustmohammadi, Andrius Vilkauskas, Giedrius Janusas. X-ray Diffraction Analysis and Williamson-Hall Method in USDM Model for Estimating More Accurate Values of Stress-Strain of Unit Cell and Super Cells (2 × 2 × 2) of Hydroxyapatite, Confirmed by Ultrasonic Pulse-Echo Test. Materials. 2021; 14 (11):2949.

Chicago/Turabian Style

Marzieh Rabiei; Arvydas Palevicius; Amir Dashti; Sohrab Nasiri; Ahmad Monshi; Akram Doustmohammadi; Andrius Vilkauskas; Giedrius Janusas. 2021. "X-ray Diffraction Analysis and Williamson-Hall Method in USDM Model for Estimating More Accurate Values of Stress-Strain of Unit Cell and Super Cells (2 × 2 × 2) of Hydroxyapatite, Confirmed by Ultrasonic Pulse-Echo Test." Materials 14, no. 11: 2949.

Journal article
Published: 22 May 2021 in Polymers
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Recently, researchers have focused on the biocompatibility and mechanical properties of highly porous structures of biomaterials products. Porous composites are a new category of bioengineering that possess excellent functional and structural properties. In this study, the physical and mechanical properties of prepared doped silver (Ag)-hydroxyapatite (HA) by the mechanochemical and spark plasma sintering (SPS) methods were investigated. The influence of dopant on phase formation, structural properties, mechanical properties and morphological characteristics was investigated. Furthermore, in this case, as a new approach to produce a porous scaffold with an average size of >100 µm, the hair band was used as a mold. According to the Monshi–Scherrer method, the crystal size of scaffold was calculated 38 ± 2 nm and this value was in the good agreement with average value from transmission electron microscopy (TEM) analysis. In addition, the stress–strain compression test of scaffold was considered, and the maximum value of compressive strength was recorded ~15.71 MPa. Taking into account the XRD, TEM, Fourier-transform infrared (FTIR), scanning electron microscope (SEM) and energy dispersive X-Ray analysis (EDAX) analysis, the prepared scaffold was bioactive and the effects of doped Ag-HA and the use of polyvinyltrimethoxysilane (PVTMS) as an additive were desirable. The results showed that the effect of thermal treatment on composed of Ag and HA were impressive while no change in transformation was observed at 850 °C. In addition, PVTMS plays an important role as an additive for preventing the decomposition and creating open-microporous in the scaffold that these porosities can be helpful for increasing bioactivity.

ACS Style

Marzieh Rabiei; Arvydas Palevicius; Reza Ebrahimi-Kahrizsangi; Sohrab Nasiri; Andrius Vilkauskas; Giedrius Janusas. New Approach for Preparing In Vitro Bioactive Scaffold Consisted of Ag-Doped Hydroxyapatite + Polyvinyltrimethoxysilane. Polymers 2021, 13, 1695 .

AMA Style

Marzieh Rabiei, Arvydas Palevicius, Reza Ebrahimi-Kahrizsangi, Sohrab Nasiri, Andrius Vilkauskas, Giedrius Janusas. New Approach for Preparing In Vitro Bioactive Scaffold Consisted of Ag-Doped Hydroxyapatite + Polyvinyltrimethoxysilane. Polymers. 2021; 13 (11):1695.

Chicago/Turabian Style

Marzieh Rabiei; Arvydas Palevicius; Reza Ebrahimi-Kahrizsangi; Sohrab Nasiri; Andrius Vilkauskas; Giedrius Janusas. 2021. "New Approach for Preparing In Vitro Bioactive Scaffold Consisted of Ag-Doped Hydroxyapatite + Polyvinyltrimethoxysilane." Polymers 13, no. 11: 1695.

Journal article
Published: 11 March 2021 in Polymers
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In recent years, natural fiber reinforced polymer composites have gained much attention over synthetic fiber composites because of their many advantages such as low-cost, light in weight, non-toxic, non-abrasive, and bio-degradable properties. Many researchers have found interest in using epoxy resin for composite fabrication over other thermosetting and thermoplastic polymers due to its dimensional stability and mechanical properties. In this research work, the mechanical and moisture properties of Caryota and sisal fiber-reinforced epoxy resin hybrid composites were investigated. The main objective of these studies is to develop hybrid composites and exploit their importance over single fiber composites. The Caryota and sisal fiber reinforced epoxy resin composites were fabricated by using the hand lay-up technique. A total of five different samples (40C/0S, 25C/15S, 20C/20S, 15C/25S, 0C/40S) were developed based on the rule of hybridization. The samples were allowed for testing to evaluate their mechanical, moisture properties and the morphology was studied by using the scanning electron microscope analysis. It was observed that hybrid composites have shown improved mechanical properties over the single fiber (Individual fiber) composites. The moisture studies stated that all the composites were responded to the water absorption but single fiber composites absorbed more moisture than hybrid composites.

ACS Style

Ayyappa Atmakuri; Arvydas Palevicius; Lalitnarayan Kolli; Andrius Vilkauskas; Giedrius Janusas. Development and Analysis of Mechanical Properties of Caryota and Sisal Natural Fibers Reinforced Epoxy Hybrid Composites. Polymers 2021, 13, 864 .

AMA Style

Ayyappa Atmakuri, Arvydas Palevicius, Lalitnarayan Kolli, Andrius Vilkauskas, Giedrius Janusas. Development and Analysis of Mechanical Properties of Caryota and Sisal Natural Fibers Reinforced Epoxy Hybrid Composites. Polymers. 2021; 13 (6):864.

Chicago/Turabian Style

Ayyappa Atmakuri; Arvydas Palevicius; Lalitnarayan Kolli; Andrius Vilkauskas; Giedrius Janusas. 2021. "Development and Analysis of Mechanical Properties of Caryota and Sisal Natural Fibers Reinforced Epoxy Hybrid Composites." Polymers 13, no. 6: 864.

Journal article
Published: 06 March 2021 in Materials
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Calcium titanate-CaTiO3 (perovskite) has been used in various industrial applications due to its dopant/doping mechanisms. Manipulation of defective grain boundaries in the structure of perovskite is essential to maximize mechanical properties and stability; therefore, the structure of perovskite has attracted attention, because without fully understanding the perovskite structure and diffracted planes, dopant/doping mechanisms cannot be understood. In this study, the areas and locations of atoms and diffracted planes were designed and investigated. In this research, the relationship between Young’s modulus and planar density of unit cell, super cells (2 × 2 × 2) and symmetry cells of nano CaTiO3 is investigated. Elastic constant, elastic compliance and Young’s modulus value were recorded with the ultrasonic pulse-echo technique. The results were C11 = 330.89 GPa, C12 = 93.03 GPa, C44 = 94.91 GPa and E = 153.87 GPa respectively. Young’s modulus values of CaTiO3 extracted by planar density were calculated 162.62 GPa, 151.71 GPa and 152.21 GPa for unit cell, super cells (2 × 2 × 2) and symmetry cells, respectively. Young’s modulus value extracted by planar density of symmetry cells was in good agreement with Young’s modulus value measured via ultrasonic pulse-echo.

ACS Style

Marzieh Rabiei; Arvydas Palevicius; Sohrab Nasiri; Amir Dashti; Andrius Vilkauskas; Giedrius Janusas. Relationship between Young’s Modulus and Planar Density of Unit Cell, Super Cells (2 × 2 × 2), Symmetry Cells of Perovskite (CaTiO3) Lattice. Materials 2021, 14, 1258 .

AMA Style

Marzieh Rabiei, Arvydas Palevicius, Sohrab Nasiri, Amir Dashti, Andrius Vilkauskas, Giedrius Janusas. Relationship between Young’s Modulus and Planar Density of Unit Cell, Super Cells (2 × 2 × 2), Symmetry Cells of Perovskite (CaTiO3) Lattice. Materials. 2021; 14 (5):1258.

Chicago/Turabian Style

Marzieh Rabiei; Arvydas Palevicius; Sohrab Nasiri; Amir Dashti; Andrius Vilkauskas; Giedrius Janusas. 2021. "Relationship between Young’s Modulus and Planar Density of Unit Cell, Super Cells (2 × 2 × 2), Symmetry Cells of Perovskite (CaTiO3) Lattice." Materials 14, no. 5: 1258.

Journal article
Published: 12 January 2021 in Sensors
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This research paper is concentrated on the design of biologically compatible lead-free piezoelectric composites which may eventually replace traditional lead zirconium titanate (PZT) in micromechanical fluidics, the predominantly used ferroelectric material today. Thus, a lead-free barium–calcium zirconate titanate (BCZT) composite was synthesized, its crystalline structure and size, surface morphology, chemical, and piezoelectric properties were analyzed, together with the investigations done in variation of composite thin film thickness and its effect on the element properties. Four elements with different thicknesses of BCZT layers were fabricated and investigated in order to design a functional acoustophoresis micromechanical fluidic element, based on bulk acoustic generation for particle control technologies. Main methods used in this research were as follows: FTIR and XRD for evaluation of chemical and phase composition; SEM—for surface morphology; wettability measurements were used for surface free energy evaluation; a laser triangular sensing system—for evaluation of piezoelectric properties. XRD results allowed calculating the average crystallite size, which was 65.68 Å3 confirming the formation of BCZT nanoparticles. SEM micrographs results showed that BCZT thin films have some porosities on the surface with grain size ranging from 0.2 to 7.2 µm. Measurements of wettability showed that thin film surfaces are partially wetting and hydrophilic, with high degree of wettability and strong solid/liquid interactions for liquids. The critical surface tension was calculated in the range from 20.05 to 27.20 mN/m. Finally, investigations of piezoelectric properties showed significant results of lead-free piezoelectric composite, i.e., under 5 N force impulse thin films generated from 76 mV up to 782 mV voltages. Moreover, an experimental analysis showed that a designed lead-free BCZT element creates bulk acoustic waves and allows manipulating bio particles in this fluidic system.

ACS Style

Tomas Janusas; Sigita Urbaite; Arvydas Palevicius; Sohrab Nasiri; Giedrius Janusas. Biologically Compatible Lead-Free Piezoelectric Composite for Acoustophoresis Based Particle Manipulation Techniques. Sensors 2021, 21, 483 .

AMA Style

Tomas Janusas, Sigita Urbaite, Arvydas Palevicius, Sohrab Nasiri, Giedrius Janusas. Biologically Compatible Lead-Free Piezoelectric Composite for Acoustophoresis Based Particle Manipulation Techniques. Sensors. 2021; 21 (2):483.

Chicago/Turabian Style

Tomas Janusas; Sigita Urbaite; Arvydas Palevicius; Sohrab Nasiri; Giedrius Janusas. 2021. "Biologically Compatible Lead-Free Piezoelectric Composite for Acoustophoresis Based Particle Manipulation Techniques." Sensors 21, no. 2: 483.

Journal article
Published: 27 November 2020 in Polymers
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Natural fibers have many advantages over synthetic fibers due to their lightness, low cost, biodegradability, and abundance in nature. The demand for natural fiber hybrid composites in various applications has increased recently, because of its promising mechanical properties. In this research work, the mechanical and wettability properties of reinforced natural fiber epoxy resin hybrid composites were investigated. The main aim of this research work is the fabrication of hybrid composites and exploit its importance over individual fiber composites. The composites were fabricated based on the rule of hybridization mixture (0.4 wf) of two fibers using sets of either hemp and flax or banana and pineapple, each set with 40 wt%, as well as four single fiber composites, 40 wt% each, as reinforcement and epoxy resin as matrix material. A total of two sets (hemp/flax and banana/pineapple) of hybrid composites were fabricated by using a hand layup technique. One set as 40H/0F, 25H/15F, 20H/20F, 15H/25F, 0H/40F, and the second one as 40B/0P, 25B/15P, 20B/20P, 15B/25P, 0B/40P weight fraction ratios. The fabricated composites were allowed for testing to examine its mechanical, wettability, and moisture properties. It has been observed that, in both cases, hybrid composites showed improved mechanical properties when compared to the individual fiber composites. The wettability test was carried out by using the contact angle measurement technique. All composites in both cases, hybrid or single showed contact angle less than 90°, which is associated with the composite hydrophilic surface properties. The moisture analysis stated that all the composites responded for moisture absorption up to 96 h and then remained constant in both cases. Hybrid composites absorbed less moisture than individual fiber composites.

ACS Style

Ayyappa Atmakuri; Arvydas Palevicius; Madhusudan Siddabathula; Andrius Vilkauskas; Giedrius Janusas. Analysis of Mechanical and Wettability Properties of Natural Fiber-Reinforced Epoxy Hybrid Composites. Polymers 2020, 12, 2827 .

AMA Style

Ayyappa Atmakuri, Arvydas Palevicius, Madhusudan Siddabathula, Andrius Vilkauskas, Giedrius Janusas. Analysis of Mechanical and Wettability Properties of Natural Fiber-Reinforced Epoxy Hybrid Composites. Polymers. 2020; 12 (12):2827.

Chicago/Turabian Style

Ayyappa Atmakuri; Arvydas Palevicius; Madhusudan Siddabathula; Andrius Vilkauskas; Giedrius Janusas. 2020. "Analysis of Mechanical and Wettability Properties of Natural Fiber-Reinforced Epoxy Hybrid Composites." Polymers 12, no. 12: 2827.

Journal article
Published: 01 October 2020 in Materials
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Young’s modulus (E) is one of the most important parameters in the mechanical properties of solid materials. Young’s modulus is proportional to the stress and strain values. There are several experimental and theoretical methods for gaining Young’s modulus values, such as stress–strain curves in compression and tensile tests, electromagnetic-acoustic resonance, ultrasonic pulse echo and density functional theory (DFT) in different basis sets. Apparently, preparing specimens for measuring Young’s modulus through the experimental methods is not convenient and it is time-consuming. In addition, for calculating Young’s modulus values by software, presumptions of data and structures are needed. Therefore, this new method for gaining the Young’s modulus values of crystalline materials is presented. Herein, the new method for calculating Young’s modulus of crystalline materials is extracted by X-ray diffraction. In this study, Young’s modulus values were gained through the arbitrary planes such as random (hkl) in the research. In this study, calculation of Young’s modulus through the relationship between elastic compliances, geometry of the crystal lattice and the planar density of each plane is obtained by X-ray diffraction. Sodium chloride (NaCl) with crystal lattices of FCC was selected as the example. The X-ray diffraction, elastic stiffness constant and elastic compliances values have been chosen by the X’Pert software, literature and experimental measurements, respectively. The elastic stiffness constant and Young’s modulus of NaCl were measured by the ultrasonic technique and, finally, the results were in good agreement with the new method of this study. The aim of the modified Williamson–Hall (W–H) method in the uniform stress deformation model (USDM) utilized in this paper is to provide a new approach of using the W–H equation, so that a least squares technique can be applied to minimize the sources of errors.

ACS Style

Marzieh Rabiei; Arvydas Palevicius; Amir Dashti; Sohrab Nasiri; Ahmad Monshi; Andrius Vilkauskas; Giedrius Janusas. Measurement Modulus of Elasticity Related to the Atomic Density of Planes in Unit Cell of Crystal Lattices. Materials 2020, 13, 4380 .

AMA Style

Marzieh Rabiei, Arvydas Palevicius, Amir Dashti, Sohrab Nasiri, Ahmad Monshi, Andrius Vilkauskas, Giedrius Janusas. Measurement Modulus of Elasticity Related to the Atomic Density of Planes in Unit Cell of Crystal Lattices. Materials. 2020; 13 (19):4380.

Chicago/Turabian Style

Marzieh Rabiei; Arvydas Palevicius; Amir Dashti; Sohrab Nasiri; Ahmad Monshi; Andrius Vilkauskas; Giedrius Janusas. 2020. "Measurement Modulus of Elasticity Related to the Atomic Density of Planes in Unit Cell of Crystal Lattices." Materials 13, no. 19: 4380.

Review
Published: 14 September 2020 in Polymers
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The present review article provides an overview of the properties of various natural and synthetic fibers for the fabrication of pure natural composites and the combination of both natural/synthetic fibers-based hybrid composites, bio-based resins, various fabrication techniques, chemical and mechanical properties of fibers, the effect of chemical treatment and the influence of nanoparticles on the composite materials. Natural fibers are becoming more popular and attractive to researchers, with satisfactory results, due to their availability, ease of fabrication, cost-effectiveness, biodegradable nature and being environmentally friendly. Hybrid composites made up of two different natural fibers under the same matrix material are more popular than a combination of natural and synthetic fibers. Recent studies relevant to natural fiber hybrid composites have stated that, due to their biodegradability and the strength of individual fibers causing an impact on mechanical properties, flame retardancy and moisture absorption, natural fibers need an additional treatment like chemical treatment for the fibers to overcome those drawbacks and to enhance their better properties. The result of chemical treatment on composite material properties such as thermal, mechanical and moisture properties was studied. Researchers found that the positive influence on overall strength by placing the filler materials (nanoparticles) in the composite materials. Hybrid composites are one of the fields in polymer science that are attracting consideration for various lightweight applications in a wide range of industries such as automobile, construction, shipping, aviation, sports equipment, electronics, hardware and biomedical sectors.

ACS Style

Ayyappa Atmakuri; Arvydas Palevicius; Andrius Vilkauskas; Giedrius Janusas. Review of Hybrid Fiber Based Composites with Nano Particles—Material Properties and Applications. Polymers 2020, 12, 2088 .

AMA Style

Ayyappa Atmakuri, Arvydas Palevicius, Andrius Vilkauskas, Giedrius Janusas. Review of Hybrid Fiber Based Composites with Nano Particles—Material Properties and Applications. Polymers. 2020; 12 (9):2088.

Chicago/Turabian Style

Ayyappa Atmakuri; Arvydas Palevicius; Andrius Vilkauskas; Giedrius Janusas. 2020. "Review of Hybrid Fiber Based Composites with Nano Particles—Material Properties and Applications." Polymers 12, no. 9: 2088.

Conference paper
Published: 08 September 2020 in Nanomaterials for Security
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Plasmon metal nanostructures are fundamental components integrated in sensing system of MEMS applications, mostly medicine and pharmacy. This paper cover main design aspects of microperiodic structures formed in different type nanocomposite films: metal/polymer with SPR effect and metal/polymer piezocomposite elements for detection and sensing purposes. Mathematical model of the system, using designed piezocomposite material with controllable properties by ultrahigh frequency excitation, was developed. This model allows to analyze the mechanical parameters of the system, which enables to control motion of cell-biological mechanisms in bio suspension and to force them to be attracted by metal nanoparticles, deposited on designed microperiodic structure in nanocomposite layer.

ACS Style

T. Janusas; S. Urbaite. Plasmon Metal Nanostructures Formation in Piezocomposite Material Controllable in Micrometric Level for Detection and Sensing Cell–Biological Particles. Nanomaterials for Security 2020, 171 -183.

AMA Style

T. Janusas, S. Urbaite. Plasmon Metal Nanostructures Formation in Piezocomposite Material Controllable in Micrometric Level for Detection and Sensing Cell–Biological Particles. Nanomaterials for Security. 2020; ():171-183.

Chicago/Turabian Style

T. Janusas; S. Urbaite. 2020. "Plasmon Metal Nanostructures Formation in Piezocomposite Material Controllable in Micrometric Level for Detection and Sensing Cell–Biological Particles." Nanomaterials for Security , no. : 171-183.

Journal article
Published: 19 August 2020 in Nanomaterials
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We report on a comparison of methods based on XRD patterns for calculating crystal size. In this case, XRD peaks were extracted from hydroxyapatite obtained from cow, pig, and chicken bones. Hydroxyapatite was synthesized through the thermal treatment of natural bones at 950 °C. XRD patterns were selected by adjustment of X-Pert software for each method and for calculating the size of the crystals. Methods consisted of Scherrer (three models), Monshi–Scherrer, three models of Williamson–Hall (namely the Uniform Deformation Model (UDM), the Uniform Stress Deformation Model (USDM), and the Uniform Deformation Energy Density Model (UDEDM)), Halder–Wanger (H-W), and the Size Strain Plot Method (SSP). These methods have been used and compared together. The sizes of crystallites obtained by the XRD patterns in each method for hydroxyapatite from cow, pig, and chicken were 1371, 457, and 196 nm in the Scherrer method when considering all of the available peaks together (straight line model). A new model (straight line passing the origin) gave 60, 60, and 53 nm, which shows much improvement. The average model gave 56, 58, and 52 nm, for each of the three approaches, respectively, for cow, pig, and chicken. The Monshi–Scherrer method gave 60, 60, and 57 nm. Values of 56, 62, and 65 nm were given by the UDM method. The values calculated by the USDM method were 60, 62, and 62 nm. The values of 62, 62, and 65 nm were given by the UDEDM method for cow, pig, and chicken, respectively. Furthermore, the crystal size value was 4 nm for all samples in the H-W method. Values were also calculated as 43, 62, and 57 nm in the SSP method for cow, pig, and chicken tandemly. According to the comparison of values in each method, the Scherrer method (straight line model) for considering all peaks led to unreasonable values. Nevertheless, other values were in the acceptable range, similar to the reported values in the literature. Experimental analyses, such as specific surface area by gas adsorption (Brunauer–Emmett–Teller (BET)) and Transmission Electron Microscopy (TEM), were utilized. In the final comparison, parameters of accuracy, ease of calculations, having a check point for the researcher, and difference between the obtained values and experimental analysis by BET and TEM were considered. The Monshi–Scherrer method provided ease of calculation and a decrease in errors by applying least squares to the linear plot. There is a check point for this line that the slope must not be far from one. Then, the intercept gives the most accurate crystal size. In this study, the setup of values for BET (56, 52, and 49 nm) was also similar to the Monshi–Scherrer method and the use of it in research studies of nanotechnology is advised.

ACS Style

Marzieh Rabiei; Arvydas Palevicius; Ahmad Monshi; Sohrab Nasiri; Andrius Vilkauskas; Giedrius Janusas. Comparing Methods for Calculating Nano Crystal Size of Natural Hydroxyapatite Using X-Ray Diffraction. Nanomaterials 2020, 10, 1627 .

AMA Style

Marzieh Rabiei, Arvydas Palevicius, Ahmad Monshi, Sohrab Nasiri, Andrius Vilkauskas, Giedrius Janusas. Comparing Methods for Calculating Nano Crystal Size of Natural Hydroxyapatite Using X-Ray Diffraction. Nanomaterials. 2020; 10 (9):1627.

Chicago/Turabian Style

Marzieh Rabiei; Arvydas Palevicius; Ahmad Monshi; Sohrab Nasiri; Andrius Vilkauskas; Giedrius Janusas. 2020. "Comparing Methods for Calculating Nano Crystal Size of Natural Hydroxyapatite Using X-Ray Diffraction." Nanomaterials 10, no. 9: 1627.

Journal article
Published: 09 July 2020 in Sensors
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A concept of a nanoporous anodic aluminum oxide (AAO) membrane as a vibro-active micro/nano-filter in a micro hydro mechanical system for the filtration, separation, and manipulation of bioparticles is reported in this paper. For the fabrication of a nanoporous AAO, a two-step mild anodization (MA) and hard anodization (HA) technique was used. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to analyze the surface morphology of nanoporous AAO. A nanoporous structure with a pore diameter in the range of 50–90 nm, an interpore distance of 110 nm, and an oxide layer thickness of 0.12 mm with 60.72% porosity was obtained. Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDS) were employed to evaluate AAO chemical properties. The obtained results showed that the AAO structure is of hexagonal symmetry and showed where Al2O3 is dominant. The hydrophobic properties of the nanoporous surface were characterized by water contact angle measurement. It was observed that the surface of the nanoporous AAO membrane is hydrophilic. Furthermore, to determine whether a nanomembrane could function as a vibro-active nano filter, a numerical simulation was performed using COMSOL Multiphysics 5.4 (COMSOL Inc, Stockholm, Sweden). Here, a membrane was excited at a frequency range of 0–100 kHz for surface acoustics wave (SAW) distribution on the surface of the nanoporous AAO using a PZT 5H cylinder (Piezo Hannas, Wuhan, China). The SAW, standing acoustic waves, and travelling acoustic waves of different wavelengths were excited to the fabricated AAO membrane and the results were compared with experimental ones, obtained from non-destructive testing method 3D scanning vibrometer (PSV-500-3D-HV, Polytec GmbH, Waldbronn, Germany) and holographic interferometry system (PRISM, Hy-Tech Forming Systems (USA), Phoenix, AZ, USA). Finally, a simulation of a single nanotube was performed to analyze the acoustic pressure distribution and time, needed to center nanoparticles in the nanotube.

ACS Style

Yatinkumar Patel; Giedrius Janusas; Arvydas Palevicius; Andrius Vilkauskas. Development of Nanoporous AAO Membrane for Nano Filtration Using the Acoustophoresis Method. Sensors 2020, 20, 3833 .

AMA Style

Yatinkumar Patel, Giedrius Janusas, Arvydas Palevicius, Andrius Vilkauskas. Development of Nanoporous AAO Membrane for Nano Filtration Using the Acoustophoresis Method. Sensors. 2020; 20 (14):3833.

Chicago/Turabian Style

Yatinkumar Patel; Giedrius Janusas; Arvydas Palevicius; Andrius Vilkauskas. 2020. "Development of Nanoporous AAO Membrane for Nano Filtration Using the Acoustophoresis Method." Sensors 20, no. 14: 3833.

Journal article
Published: 04 December 2019 in Mechanics
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The paper is dedicated to analysis, practical exploitation of sonotrode, whose fundament is multilayer actuator in experiments of mechanical hot imprint. The goal is to compare the quality of microstructures, created by using vibration based on multilayer actuator. Numerical modelling and experimental analysis is performed in order to find resonant frequency of the sonotrode. Having operating frequency, sonotrode applied in mechanical hot imprint process. Microstructures are created on the surface of polycarbonate; the only process variable is vibration. Two types of microstructure quality measurements are performed: measurement of diffraction efficiency, optical microscopy in order to examine quality of replica

ACS Style

Amer Sodah; Arvydas Palevicius; Giedrius Janusas; Paulius Palevicius; Yatinkumar Patel. Numerical and Experimental Investigation of Sonotrode for Formation of Piezocomposite Functional Elements. Mechanics 2019, 25, 463 -472.

AMA Style

Amer Sodah, Arvydas Palevicius, Giedrius Janusas, Paulius Palevicius, Yatinkumar Patel. Numerical and Experimental Investigation of Sonotrode for Formation of Piezocomposite Functional Elements. Mechanics. 2019; 25 (6):463-472.

Chicago/Turabian Style

Amer Sodah; Arvydas Palevicius; Giedrius Janusas; Paulius Palevicius; Yatinkumar Patel. 2019. "Numerical and Experimental Investigation of Sonotrode for Formation of Piezocomposite Functional Elements." Mechanics 25, no. 6: 463-472.

Journal article
Published: 29 April 2019 in Sensors
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The concept of active microchannel for precise manipulation of particles in biomedicine is reported in this paper. A novel vibration-assisted thermal imprint method is proposed for effective formation of a microchannel network in the nanocomposite piezo polymer layer. In this method, bulk acoustic waves of different wavelengths excited in an imprinted microstructure enable it to function in trapping–patterning, valve, or free particle passing modes. Acoustic waves are excited using a special pattern of electrodes formed on its top surface and a single electric ground electrode formed on the bottom surface. To develop the microchannel, we first started with lead zirconate titanate (PZT) nanopowder [Pb (Zrx, Ti1–x) O3] synthesis. The PZT was further mixed with three different binding materials—polyvinyl butyral (PVB), poly(methyl methacrylate) (PMMA), and polystyrene (PS)—in benzyl alcohol to prepare a screen-printing paste. Then, using conventional screen printing techniques, three types of PZT coatings on copper foil substrates were obtained. To improve the voltage characteristics, the coatings were polarized. Their structural and chemical composition was analyzed using scanning electron microscope (SEM), while the mechanical and electrical characteristics were determined using the COMSOL Multiphysics model with experimentally obtained parameters of periodic response of the layered copper foil structure. The hydrophobic properties of the PZT composite were analyzed by measuring the contact angle between the distilled water drop and the three different polymer composites: PZT with PVB, PZT with PMMA, and PZT with PS. Finally, the behavior of the microchannel formed in the nanocomposite piezo polymer was simulated by applying electrical excitation signal on the pattern of electrodes and then analyzed experimentally using holographic interferometry. Wave-shaped vibration forms of the microchannel were obtained, thereby enabling particle manipulation.

ACS Style

Giedrius Janusas; Kestutis Pilkauskas; Arvydas Palevicius. Active PZT Composite Microfluidic Channel for Bioparticle Manipulation. Sensors 2019, 19, 2020 .

AMA Style

Giedrius Janusas, Kestutis Pilkauskas, Arvydas Palevicius. Active PZT Composite Microfluidic Channel for Bioparticle Manipulation. Sensors. 2019; 19 (9):2020.

Chicago/Turabian Style

Giedrius Janusas; Kestutis Pilkauskas; Arvydas Palevicius. 2019. "Active PZT Composite Microfluidic Channel for Bioparticle Manipulation." Sensors 19, no. 9: 2020.

Journal article
Published: 20 November 2018 in Sensors
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This paper reviews recent investigations and achievements in the design of controllable functional components for improving microfluidic systems, its effectiveness, and functionality. The main purpose was to design novel microstructures with piezoelectric properties (microresonators), which enable one to control the effectiveness of fluid flow in micro-hydro-mechanical devices for biomedical/biochemical purposes. Controllable properties were obtained by incorporating different types of binders in a piezoelectric ceramic matrix (lead zirconate titanate): polyvinyl butyral (PVB), poly methyl methacrylate (PMMA), and polystyrene (PS). The change in chemical composition of PZT helps to manipulate the piezoelectric characteristics, surface morphology, mechanical properties, etc., of the designed microfluidic element with the microstructure in it.

ACS Style

Elingas Cekas; Giedrius Janusas; Asta Guobiene; Arvydas Palevicius; Andrius Vilkauskas; Sigita Ponelyte Urbaite. Design of Controllable Novel Piezoelectric Components for Microfluidic Applications. Sensors 2018, 18, 4049 .

AMA Style

Elingas Cekas, Giedrius Janusas, Asta Guobiene, Arvydas Palevicius, Andrius Vilkauskas, Sigita Ponelyte Urbaite. Design of Controllable Novel Piezoelectric Components for Microfluidic Applications. Sensors. 2018; 18 (11):4049.

Chicago/Turabian Style

Elingas Cekas; Giedrius Janusas; Asta Guobiene; Arvydas Palevicius; Andrius Vilkauskas; Sigita Ponelyte Urbaite. 2018. "Design of Controllable Novel Piezoelectric Components for Microfluidic Applications." Sensors 18, no. 11: 4049.

Journal article
Published: 24 September 2018 in Vibroengineering PROCEDIA
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Giedrius Janušas; Tomas Janušas; Arvydas Palevičius. Methodology for identification of liquid concentration in the periodic microstructures applying numerical-experimental laser interferometric methods. Vibroengineering PROCEDIA 2018, 19, 216 -220.

AMA Style

Giedrius Janušas, Tomas Janušas, Arvydas Palevičius. Methodology for identification of liquid concentration in the periodic microstructures applying numerical-experimental laser interferometric methods. Vibroengineering PROCEDIA. 2018; 19 ():216-220.

Chicago/Turabian Style

Giedrius Janušas; Tomas Janušas; Arvydas Palevičius. 2018. "Methodology for identification of liquid concentration in the periodic microstructures applying numerical-experimental laser interferometric methods." Vibroengineering PROCEDIA 19, no. : 216-220.

Technical paper
Published: 31 May 2018 in Microsystem Technologies
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In this article, thermal imprint process for replication of high-quality microstructures on the surface of polymer is investigated. Vibrations has been previously employed as an additional measure to enhance the replicability of microstructure into the pre-heated polymer. On the other hand, polymer behavior under the action of vibrations is not sufficiently studied. In this article, thermal microstructure replication is modeled and simulated by applying vibratory assisted thermal imprint to provide a better comprehension of the replication process peculiarities that would lead to improvement of the replication process itself. Different aspects of the process are analyzed: depth of imprinted pattern, pressure, traction force, residual field of plastic deformations and stresses. Numerical simulation results are verified experimentally. The results of the research shows that process assistance with vibratory excitation results in higher imprint depth compared with the specimens, imprinted under the identical process conditions without vibratory excitation.

ACS Style

Amer Sodah; Rimvydas Gaidys; Birute Narijauskaite; Rokas Sakalys; Giedrius Janušas; Arvydas Palevičius; Paulius Palevičius. Analysis of microstructure replication using vibratory assisted thermal imprint process. Microsystem Technologies 2018, 25, 477 -486.

AMA Style

Amer Sodah, Rimvydas Gaidys, Birute Narijauskaite, Rokas Sakalys, Giedrius Janušas, Arvydas Palevičius, Paulius Palevičius. Analysis of microstructure replication using vibratory assisted thermal imprint process. Microsystem Technologies. 2018; 25 (2):477-486.

Chicago/Turabian Style

Amer Sodah; Rimvydas Gaidys; Birute Narijauskaite; Rokas Sakalys; Giedrius Janušas; Arvydas Palevičius; Paulius Palevičius. 2018. "Analysis of microstructure replication using vibratory assisted thermal imprint process." Microsystem Technologies 25, no. 2: 477-486.

Conference paper
Published: 28 March 2018 in Computer Vision
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‘Lab-on-a-chip’ is integrated micro-analytical system, which could perform sample pre-treatment, chemical reactions, analytical separation, detection and data handling. These platforms are able to convert biological, chemical or mechanical responses into electrical signals using the piezoelectric or piezoresistive materials. This paper discusses a piezoelectric composite material displaying its mechanical properties such as resonant frequencies, Young’s modulus and density. Nano composite polymer highlights the property of piezo effect and is suitable for formation of periodic micro scale patterns on it. These micro patterns are intended to be used as innovative functional elements in biomedical micro hydro mechanical systems such as micro channels. Thus by controlling surface configuration and the shape of active deformable polymer, pressure in microfluidic vessels can be changed and mobility of the transported bioparticles can be ensured.

ACS Style

Arvydas Palevicius; Giedrius Janusas; Elingas Cekas; YatinkumarRajeshbhai Patel. Composite Piezoelectric Material for Biomedical Micro Hydraulic System. Computer Vision 2018, 49 -58.

AMA Style

Arvydas Palevicius, Giedrius Janusas, Elingas Cekas, YatinkumarRajeshbhai Patel. Composite Piezoelectric Material for Biomedical Micro Hydraulic System. Computer Vision. 2018; ():49-58.

Chicago/Turabian Style

Arvydas Palevicius; Giedrius Janusas; Elingas Cekas; YatinkumarRajeshbhai Patel. 2018. "Composite Piezoelectric Material for Biomedical Micro Hydraulic System." Computer Vision , no. : 49-58.

Journal article
Published: 26 February 2018 in Mechanics
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The aim of this paper is to propose a novel structure glucose sensor which makes glucose level measurement system more convenient, increases measurement accuracy and gets the sensor that can be manufactured applying cheap manufacture processes. The main focus is made on the design of viscoelastic cantilever type sensors with the embedded piezo-active functional element to drive micro cantilever in order to detect concentration of glucose in the physiological liquid. Analytical, numerical and experimental methods for design and analysis of viscoelastic sensor are presented. DOI: http://dx.doi.org/10.5755/j01.mech.24.1.19230

ACS Style

Giedrius Janušas; Alfredas Brunius; Christopher Rayappan; Arvydas Palevicius; Kęstutis Pilkauskas; Tomas Janušas. Design and Analysis of Viscometric Sensor with Embedded Microstruc-ture for Biomedical Applications. Mechanics 2018, 24, 115 - 120 .

AMA Style

Giedrius Janušas, Alfredas Brunius, Christopher Rayappan, Arvydas Palevicius, Kęstutis Pilkauskas, Tomas Janušas. Design and Analysis of Viscometric Sensor with Embedded Microstruc-ture for Biomedical Applications. Mechanics. 2018; 24 (1):115 - 120.

Chicago/Turabian Style

Giedrius Janušas; Alfredas Brunius; Christopher Rayappan; Arvydas Palevicius; Kęstutis Pilkauskas; Tomas Janušas. 2018. "Design and Analysis of Viscometric Sensor with Embedded Microstruc-ture for Biomedical Applications." Mechanics 24, no. 1: 115 - 120.

Proceedings article
Published: 19 February 2018 in Microfluidics, BioMEMS, and Medical Microsystems XVI
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Cantilever and membrane based sensors, which are capable of providing accurate detection of target analytes have been always an important research topic of medical diagnostics, food testing, and environmental monitoring fields. Here, the mechanical detection is achieved by micro- and nano-scale cantilevers for stress sensing and mass sensing, or micro- and nano-scale plates or membranes. High sensitivity is a major issue for the active element and it could be achieved via increased Q-factor. The ability to control the Q factor expands the range of application of the device and allows to achieve more accurate results. The aim of this paper is to investigate the mechanical and electrical properties, as well as, the ability to control the Q factor of the membrane with PZT nanocomposite. This multilayered membrane was formatted using the n-type silicon substrate by implementing the Low Pressure Chemical Vapor Deposition (LPCVD), photolithography by using photomask with defined dimensions, deep etching, and e-beam evaporation techniques. Dynamic and electrical characteristics of the membrane were numerically investigated using COMSOL Multiphysics software. The use of the multilayered membrane can range from simple monitoring of particles concentration in a closed environment to inspecting glucose levels in human fluids (blood, tears, sweat, etc.).

ACS Style

Giedrius Janušas; Elingas Čekas; Arvydas Palevicius; Justas Ciganas; Tomas Janušas. Q-factor control of multilayer micromembrane using PZT composite material. Microfluidics, BioMEMS, and Medical Microsystems XVI 2018, 10491, 104910S .

AMA Style

Giedrius Janušas, Elingas Čekas, Arvydas Palevicius, Justas Ciganas, Tomas Janušas. Q-factor control of multilayer micromembrane using PZT composite material. Microfluidics, BioMEMS, and Medical Microsystems XVI. 2018; 10491 ():104910S.

Chicago/Turabian Style

Giedrius Janušas; Elingas Čekas; Arvydas Palevicius; Justas Ciganas; Tomas Janušas. 2018. "Q-factor control of multilayer micromembrane using PZT composite material." Microfluidics, BioMEMS, and Medical Microsystems XVI 10491, no. : 104910S.

Journal article
Published: 12 December 2017 in Sensors
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This paper proposes an approach for designing an efficient vibration energy harvester based on a vibro-impacting piezoelectric microcantilever with a geometric shape that has been rationally modified in accordance with results of dynamic optimization. The design goal is to increase the amplitudes of higher-order vibration modes induced during the vibro-impact response of the piezoelectric transducer, thereby providing a means to improve the energy conversion efficiency and power output. A rational configuration of the energy harvester is proposed and it is demonstrated that the new design retains essential modal characteristics of the optimal microcantilever structures, further providing the added benefit of less costly fabrication. The effects of structural dynamics associated with advantageous exploitation of higher vibration modes are analyzed experimentally by means of laser vibrometry as well as numerically via transient simulations of microcantilever response to random excitation. Electrical characterization results indicate that the proposed harvester outperforms its conventional counterpart (based on the microcantilever of the constant cross-section) in terms of generated electrical output. Reported results may serve for the development of impact-type micropower generators with harvesting performance that is enhanced by virtue of self-excitation of large intensity higher-order mode responses when the piezoelectric transducer is subjected to relatively low-frequency excitation with strongly variable vibration magnitudes.

ACS Style

Ieva Migliniene; Vytautas Ostasevicius; Rimvydas Gaidys; Rolanas Dauksevicius; Giedrius Janusas; Vytautas Jurenas; Povilas Krasauskas. Rational Design Approach for Enhancing Higher-Mode Response of a Microcantilever in Vibro-Impacting Mode. Sensors 2017, 17, 2884 .

AMA Style

Ieva Migliniene, Vytautas Ostasevicius, Rimvydas Gaidys, Rolanas Dauksevicius, Giedrius Janusas, Vytautas Jurenas, Povilas Krasauskas. Rational Design Approach for Enhancing Higher-Mode Response of a Microcantilever in Vibro-Impacting Mode. Sensors. 2017; 17 (12):2884.

Chicago/Turabian Style

Ieva Migliniene; Vytautas Ostasevicius; Rimvydas Gaidys; Rolanas Dauksevicius; Giedrius Janusas; Vytautas Jurenas; Povilas Krasauskas. 2017. "Rational Design Approach for Enhancing Higher-Mode Response of a Microcantilever in Vibro-Impacting Mode." Sensors 17, no. 12: 2884.