scholarly journals Lightweight, Ferroelectric-Ferromagnetic Polymer- Nanocomposites for Field Sensor Applications

2021 ◽  
Author(s):  
Chakradhar Behera
Keyword(s):  
Electrical Response ◽  
Ceramic Composites ◽  
Free Standing ◽  
Weight Percentage ◽  
Casting Technique ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Flexible Polymer ◽  
Fixed Weight ◽  
Field Sensor

The coexistence of ferroelectric and magnetic order parameters in multiferroic materials opens up a host of new collective properties. In particular, the magnetoelectric (ME) effect namely the induction of electric polarization by a magnetic field or magnetization by an electric field has been widely studied in multiferroics. PVDF is a ferroelectric polymer that has attracted considerable research interest for sensing applications. Compared to traditional ceramic composites, the polymer-ceramic nanocomposites offer inherent advantages, including easy processing, mechanical flexibility and the ability to be moulded into complicated configurations for advanced devices with reduced volume and weight. Additionally, polymer composites generally exhibit superior ME coefficients, attributable to the improved displacement transfer capability of the flexible polymer matrix. In this report, free-standing, flexible and lightweight polymer–ceramic nanocomposite thin films with a fixed weight percentage of ferromagnetic CoFe2O4 nanoparticles have been fabricated using a solution casting technique. The structural, microstructural, and electrical properties of the composite have been characterized by standard experimental techniques. The structural and chemical analyses prove a homogeneous dispersion of the fillers in the microstructure of the composite. The electrical response investigated by impedance spectroscopy reveals the contributions of grains and grain boundaries to the whole impedance of the composites. The ac conductivity as a function of frequency obeys Jonscher’s power law. The improved magnetoelectric properties suggest promising applications in multifunctional devices, including field sensor applications.

scholarly journals Rapid Growth of TiO2 Nanoflowers via Low-Temperature Solution Process: Photovoltaic and Sensing Applications

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 566 ◽  
Author(s):  
M. Akhtar ◽  
Ahmad Umar ◽  
Swati Sood ◽  
InSung Jung ◽  
H. Hegazy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Anatase Phase ◽  
Three Dimensional ◽  
Solution Process ◽  
Dye Sensitized Solar Cell ◽  
Sensor Applications ◽  
Dye Sensitized ◽  
Sensing Applications ◽  
Density Growth ◽  
Temperature Solution

This paper reports the rapid synthesis, characterization, and photovoltaic and sensing applications of TiO2 nanoflowers prepared by a facile low-temperature solution process. The morphological characterizations clearly reveal the high-density growth of a three-dimensional flower-shaped structure composed of small petal-like rods. The detailed properties confirmed that the synthesized nanoflowers exhibited high crystallinity with anatase phase and possessed an energy bandgap of 3.2 eV. The synthesized TiO2 nanoflowers were utilized as photo-anode and electron-mediating materials to fabricate dye-sensitized solar cell (DSSC) and liquid nitroaniline sensor applications. The fabricated DSSC demonstrated a moderate conversion efficiency of ~3.64% with a maximum incident photon to current efficiency (IPCE) of ~41% at 540 nm. The fabricated liquid nitroaniline sensor demonstrated a good sensitivity of ~268.9 μA mM−1 cm−2 with a low detection limit of 1.05 mM in a short response time of 10 s.

The rheological behaviour and thermal ageing characteristics of PP/MWCNT/glass fibre multiscale composites

2021 ◽  
pp. 096739112199290
Author(s):  
N Rasana ◽  
K Jayanarayanan ◽  
Krishna Prasad Rajan ◽  
Aravinthan Gopanna
Keyword(s):  
Hybrid Composites ◽  
Rheological Behaviour ◽  
Strain Energy Release ◽  
Critical Stress Intensity Factor ◽  
Thermal Ageing ◽  
Multiwalled Carbon ◽  
Weight Percentage ◽  
Fixed Weight ◽  
Multiscale Composite ◽  
The Matrix

Multiscale hybrid composites were prepared using varying weight percentages (0 to 5) of multiwalled carbon nanotubes (MWCNTs) as nanofiller and a fixed weight percentage (20) of short glass fibres as micro filler (in polypropylene (PP) matrix. The shear and extensional viscosity of the composites was measured using a capillary rheometer. It was observed that even at higher shear rates the synergism of micro and nanofillers in the matrix significantly enhanced the melt viscosity. The complex nanotube network entanglement with micro fillers and PP chains imparted restrictions to the polymer chain movements. The prepared samples were subjected to thermal ageing at 100°C for 4 days in hot air oven. After ageing, multiscale composite with 3 wt% MWCNTs exhibited 28.57% enhancement in strain at break, whereas the tensile strength and modulus reduced by 6.8% and 8% respectively. The fracture toughness properties like strain energy release rate and critical stress intensity factor were not affected for multiscale composite at the optimum content of 3 wt% MWCNT, even after thermal ageing.

Rapid Silicon-to-Steel Bonding via Inductive Heating

2006 ◽  
Author(s):  
Brian D. Sosnowchik ◽  
Liwei Lin ◽  
Albert P. Pisano
Keyword(s):  
Bonding Temperature ◽  
Surface Preparation ◽  
Fatigue Tests ◽  
Bonding Process ◽  
Inductive Heating ◽  
Sensor Applications ◽  
Mems Sensor ◽  
Sensing Applications ◽  
Minimal Damage ◽  
Point Bend

In this work, we present a rapid, low temperature process for the bonding of silicon to steel through the use of inductive heating for MEMS sensor applications. The bonding process takes as short as three seconds with a maximum bonding temperature as low as 230°C at the steel surface. The bonding strength is strong, and causes minimal damage to steel. The process has also been shown to work using leaded and leadfree bonding solder with minimal surface preparation to the steel. Four characterization experiments – tensile and compressive 4-point bend, axial extension, and fatigue tests – have been performed to validate the bonding process and materials. As such, this work illustrates the promise of applying inductive heating for the rapid silicon bonding to steel components for MEMS sensing applications.

Quantum transport, electronic properties and molecular adsorptions in graphene

2021 ◽  
Vol 35 (08) ◽  
pp. 2130001
Author(s):  
Yoshitaka Fujimoto
Keyword(s):  
Electronic Properties ◽  
Quantum Transport ◽  
Density Functional ◽  
Field Effect Transistors ◽  
Electronic Conductivity ◽  
Volume Ratio ◽  
Functional Study ◽  
Sensor Applications ◽  
Sensing Applications ◽  
High Electronic Conductivity

Molecular sensor applications are used in different fields including environmental monitoring and medical diagnosis. Graphene, a single atomic layer consisting of the hexagonally arranged carbon material, is one of the most promising materials for ideal channels in field-effect transistors to be used as electronic sensing applications owing to its lightweight, mechanical robustness, high electronic conductivity and large surface-to-volume ratio. This paper provides a review of molecular adsorptions, electronic properties and quantum transport of graphene based on the first-principles density-functional study. The adsorption properties of environmentally polluting or toxic molecules and electronic transport of graphene are revealed. The possibility of detecting these molecules selectively is also discussed for designing the graphene-based sensor applications.

Fabrication of large area nanogap electrodes for sensing applications

2013 ◽  
Vol 1530 ◽  
Author(s):  
A. Bendavid ◽  
L. Wieczorek ◽  
R. Chai ◽  
J. S. Cooper ◽  
B. Raguse
Keyword(s):  
Large Scale ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Current ◽  
Fabrication Method ◽  
Large Area ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Lift Off ◽  
Nanogap Electrodes

ABSTRACTA large area nanogap electrode fabrication method combinig conventional lithography patterning with the of focused ion beam (FIB) is presented. Lithography and a lift-off process were used to pattern 50 nm thick platinum pads having an area of 300 μm × 300 μm. A range of 30-300 nm wide nanogaps (length from 300 μm to 10 mm ) were then etched using an FIB of Ga+ at an acceleration voltage of 30 kV at various beam currents. An investigation of Ga+ beam current ranging between 1-50 pA was undertaken to optimise the process for the current fabrication method. In this study, we used Monte Carlo simulation to calculate the damage depth in various materials by the Ga+. Calculation of the recoil cascades of the substrate atoms are also presented. The nanogap electrodes fabricated in this study were found to have empty gap resistances exceeding several hundred MΩ. A comparison of the gap length versus electrical resistance on glass substrates is presented. The results thus outline some important issues in low-conductance measurements. The proposed nanogap fabrication method can be extended to various sensor applications, such as chemical sensing, that employ the nanogap platform. This method may be used as a prototype technique for large-scale fabrication due to its simple, fast and reliable features.

A Novel Micromechanical Resonator Using Two-Dimensional Phononic Crystal Slab

2011 ◽  
Vol 254 ◽  
pp. 195-198
Author(s):  
Nan Wang ◽  
Fu Li Hsiao ◽  
Moorthi Palaniapan ◽  
Ming Lin Julius Tsai ◽  
Jeffrey B.W. Soon ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Phononic Crystal ◽  
Acoustic Resonance ◽  
Two Dimensional ◽  
Free Standing ◽  
Sensing Applications ◽  
Aln Film ◽  
Digital Transducers ◽  
Square Array ◽  
Quality Factor Q

Two-dimensional (2-D) Silicon phononic crystal (PnC) slab of a square array of cylindrical air holes in a 10μm thick free-standing silicon plate with line defects is characterized as a cavity-mode PnC resonator. Piezoelectric aluminum nitride (AlN) film is deployed as the inter-digital transducers (IDT) to transmit and detect acoustic waves, thus making the whole microfabrication process CMOS-compatible. Both the band structure of the PnC and the transmission spectrum of the proposed PnC resonator are analyzed and optimized using finite element method (FEM). The measured quality factor (Q factor) of the microfabricated PnC resonator is over 1,000 at its resonant frequency of 152.46MHz. The proposed PnC resonator shows promising acoustic resonance characteristics for RF communications and sensing applications.

Process optimization using grey relational analysis in dry sliding wear behavior on SiC/B4C/Talc reinforced Al 6061 hybrid metal matrix composite

2021 ◽  
Vol 118 (6) ◽  
pp. 614
Author(s):  
Chellamuthu Ramesh Kumar ◽  
Subramanian Baskar ◽  
Ganesan Ramesh ◽  
Pathinettampadian Gurusamy ◽  
Thirupathy Maridurai
Keyword(s):  
Wear Resistance ◽  
Metal Matrix ◽  
Wear Behavior ◽  
Base Alloy ◽  
Specific Weight ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Weight Percentage ◽  
Casting Technique ◽  
Grey Relational

In this research, investigations were carried out on Al6061 base alloy with the changing weight percentage of silicon carbide (SiC) and boron carbide (B4C) with keeping the amount of talc constant. The main objective of this present study was to improve the wear resistance of aluminum alloy using SiC/B4C/talc ceramic particles using stir-casting technique and how the eco-friendly talc content influencing the solid lubricity during the abrasion process. The experiments were conducted via orthogonal array of L27 using Taguchi’s method. The optimum value along with the coefficient of friction was obtained on the basis of grey relational equations and ANOVA, which helped in analysis of most influential input parameters such as applied load, sliding speed, sliding distance and percentage of reinforcement. Conformation tests were performed for the purpose of validation of the experimental results. The specimens were analyzed using scanning electron microscope (SEM) with EDX for micro structural studies. The SiC, B4C and talc presence in the composite helped to improve the mechanical properties, according to the results. The presence of solid lubricant talc as reinforcement to the aluminum hybrid composite reduced the wear properties and decreased the co-efficient friction. These wear resistance improved aluminum metal matrix composites could be used in automobile, defense and domestic applications where high strength and wear resistance required with lesser specific weight.

Fabrication and Morphological Characterization of Barium Titanate-Based Polymeric Nanocomposite Thin Films

2018 ◽  
pp. 50-59 ◽  
Author(s):  
Sudhanshu Singh ◽  
Umesh Kumar Dwivedi
Keyword(s):  
Barium Titanate ◽  
Room Temperature ◽  
Composite Films ◽  
Morphological Characterization ◽  
Solution Casting ◽  
Weight Percentage ◽  
Casting Technique ◽  
Nanocomposite Thin Films ◽  
Solution Casting Technique

In this critical review chapter, the authors explain the development of composite films of Barium Titanate (BaTiO3) and Poly (methyl methacrylate) prepared by solution casting technique. Different weight percentage composition of BaTiO3 has been selected to find out the best optimization condition for further investigation and correlate the results. The structural properties have been carried out at room temperature using XRD. Efforts have been made to correlate the results with investigated XRD results of pure BaTiO3 and its composites as observed by other workers at room temperature. The flow of experimental work and microscopic images are explained.

EXPERIMENTAL INVESTIGATIONS ON THE INFLUENCE OF TiC/GRAPHITE REINFORCEMENT IN WEAR BEHAVIOR OF Al 6061HYBRID COMPOSITES

2019 ◽  
Vol 26 (04) ◽  
pp. 1850173 ◽  
Author(s):  
S. JEYAPRAKASAM ◽  
R. VENKATACHALAM ◽  
C. VELMURUGAN
Keyword(s):  
Hybrid Composites ◽  
Wear Behavior ◽  
Research Work ◽  
Testing Machine ◽  
Wear Testing ◽  
Experimental Investigations ◽  
Sem Images ◽  
Weight Percentage ◽  
Casting Technique ◽  
Graphite Particles

This research work focuses about fabrication and investigation on the influence of Titanium Carbide (TiC)-graphite particles reinforcement in wear behavior of Aluminium Matrix Composites (AMC). The stir casting technique was used to fabricate AMC reinforced with various weight percentage of TiC and graphite particles. Wear tests were conducted by using pin-on-disc wear testing machine. The hardness of the hybrid composites were recorded on the test specimen. The worn out surfaces of composites were analyzed using Scanning Electron Microscope (SEM). Results reveal that the presence of TiC and graphite particles improved the wear resistance. The wear of composite is primarily due to delamination and abrasion. The graphite particles serve as the solid lubricant on the wear of composite. The hardness of composite is improved with the decrease in weight percentage of graphite. SEM images reveal that the reinforcement particles in the matrix are homogeneously distributed. Also, worn-out surfaces of the composite were studied to observe wear track and wear mechanisms like plowing grooves, crack or cutting, and fragmentation.

scholarly journals Large-Area Thermal Distribution Sensor Based on Multilayer Graphene Ink

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5188
Author(s):  
Tomi Koskinen ◽  
Taneli Juntunen ◽  
Ilkka Tittonen
Keyword(s):  
Signal To Noise Ratio ◽  
Graphene Film ◽  
Multilayer Graphene ◽  
Wearable Electronics ◽  
Large Area ◽  
Sensor Applications ◽  
Thermal Distribution ◽  
Sensing Applications ◽  
Detection Of Objects ◽  
Distribution Mapping

Emergent applications in wearable electronics require inexpensive sensors suited to scalable manufacturing. This work demonstrates a large-area thermal sensor based on distributed thermocouple architecture and ink-based multilayer graphene film. The proposed device combines the exceptional mechanical properties of multilayer graphene nanocomposite with the reliability and passive sensing performance enabled by thermoelectrics. The Seebeck coefficient of the spray-deposited films revealed an inverse thickness dependence with the largest value of 44.7 μV K−1 at 78 nm, which makes thinner films preferable for sensor applications. Device performance was demonstrated by touch sensing and thermal distribution mapping-based shape detection. Sensor output voltage in the latter application was on the order of 300 μV with a signal-to-noise ratio (SNR) of 35, thus enabling accurate detection of objects of different shapes and sizes. The results imply that films based on multilayer graphene ink are highly suitable to thermoelectric sensing applications, while the ink phase enables facile integration into existing fabrication processes.

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