Ghader Rezazadeh
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Ghader Rezazadeh has a total of 243 co-authors. Here are the top co-authors by number of shared publications:
- Mina Ghanbari
Mechanical Engineering Department, Urmia University of Technology, Urmia, Iran
17 shared publications Mohammad Fathalilou
17 shared publications- Rasoul Shabani
Mechanical Engineering Department, Urmia University, Urmia, Iran
17 shared publications Rasoul Shabani
Department of Mechanical Engineering, Faculty of Engineering, Urmia University, Urmia, Iran
14 shared publicationsMina Ghanbari
Faculty of Mechanical Engineering, Mechanical Engineering Department, Urmia University of Technology, Urmia, Iran
11 shared publications- Mohammad Fathalilou
Mechanical Engineering Department, Urmia University, Urmia, Iran
10 shared publications
Latest Publications
- Open Access
- 24 October 2026
- Published by Elsevier in Solar Energy
- Vol. 320
Experimentally anchored model for sputtered alumina encapsulation of perovskite films
- 24 October 2026
- Published by Elsevier in Solar Energy
- Vol. 320
Open AccessExperimentally anchored model for sputtered alumina encapsulation of perovskite films
- Open Access
- 16 October 2026
- Published by Springer Nature in Journal of Umm Al-Qura University for Applied Sciences
- p. 1-15
Nonlinear dynamics of circular microplates on displacement-dependent porous PDMS foundations for capacitive ultrasonic transducers
This study develops a comprehensive nonlinear mathematical model for the dynamic behavior of a circular microplate supported by a porous polydimethylsiloxane (PDMS) foundation with displacement-dependent porosity, relevant to capacitive micromachined ultrasonic transducers (CMUTs). The model integrates nonlinear elasticity, effective medium theory to capture dielectric variation, and accounts for the influence of displacement-dependent porosity on the system’s stiffness and electrostatic coupling. Employing dimensionless formulation and energy-based harmonic balance methods, the analysis addresses primary and secondary resonance phenomena and highlights how porous PDMS significantly reduces actuation voltage and enhances vibration amplitude and acoustic pressure compared to conventional air-gap models. Numerical simulations demonstrate the critical role of displacement-dependent porosity in improving CMUT performance, offering an effective mathematical framework for the design and optimization of soft, porous elastomeric foundations in ultrasonic devices.
- 16 October 2026
- Published by Springer Nature in Journal of Umm Al-Qura University for Applied Sciences
- p. 1-15
Open AccessNonlinear dynamics of circular microplates on displacement-dependent porous PDMS foundations for capacitive ultrasonic transducers
This study develops a comprehensive nonlinear mathematical model for the dynamic behavior of a circular microplate supported by a porous polydimethylsiloxane (PDMS) foundation with displacement-dependent porosity, relevant to capacitive micromachined ultrasonic transducers (CMUTs). The model integrates nonlinear elasticity, effective medium theory to capture dielectric variation, and accounts for the influence of displacement-dependent porosity on the system’s stiffness and electrostatic coupling. Employing dimensionless formulation and energy-based harmonic balance methods, the analysis addresses primary and secondary resonance phenomena and highlights how porous PDMS significantly reduces actuation voltage and enhances vibration amplitude and acoustic pressure compared to conventional air-gap models. Numerical simulations demonstrate the critical role of displacement-dependent porosity in improving CMUT performance, offering an effective mathematical framework for the design and optimization of soft, porous elastomeric foundations in ultrasonic devices.
- Open Access
- 29 September 2026
- Published by Springer Nature in Scientific Reports
A multi-physics framework for optimizing FBG sensor thermal response via nanoparticle-engineered polymer coatings
Fiber Bragg grating (FBG) sensors are widely used for precise temperature monitoring, but standard polymer coatings often introduce thermal lag during rapid temperature fluctuations. While incorporating thermally conductive nanoparticles can accelerate heat transfer, high filler loadings typically cause agglomeration, increase interfacial (Kapitza) resistance, and compromise mechanical integrity. This study introduces a unified multi-physics framework to optimize nanoparticle–polymer coatings for FBG sensors without relying on high filler concentrations. The proposed model couples transient heat conduction, effective medium homogenization, and thermo-mechanical strain transfer, explicitly accounting for interfacial resistance, percolation-driven conductivity, fabrication-induced porosity, and strain-transfer efficiency. For randomly dispersed fillers, effective properties are predicted using coupled homogenization and percolation models. For engineered or oriented architectures, the framework directly integrates experimentally validated thermal and mechanical properties. Numerical results predict that at 5.8 vol%, graphene nanoplatelets can reduce the thermal response time by approximately 80% compared to a pure polymer coating, while silica nanoparticles are projected to extend the maximum operational temperature by approximately 27 K. Metallic fillers (Ag, Au) improve heat transfer but show limited high-temperature stability due to oxidation and interfacial resistance. The framework identifies optimal loading windows that balance thermal response time, mechanical integrity, and thermal durability. These findings provide practical, physics-based design guidelines for next-generation FBG sensors and establish the mechanistic foundation for adaptive, physics-informed Digital Twins tailored to aerospace, industrial, and biomedical applications.
- 29 September 2026
- Published by Springer Nature in Scientific Reports
Open AccessA multi-physics framework for optimizing FBG sensor thermal response via nanoparticle-engineered polymer coatings
Fiber Bragg grating (FBG) sensors are widely used for precise temperature monitoring, but standard polymer coatings often introduce thermal lag during rapid temperature fluctuations. While incorporating thermally conductive nanoparticles can accelerate heat transfer, high filler loadings typically cause agglomeration, increase interfacial (Kapitza) resistance, and compromise mechanical integrity. This study introduces a unified multi-physics framework to optimize nanoparticle–polymer coatings for FBG sensors without relying on high filler concentrations. The proposed model couples transient heat conduction, effective medium homogenization, and thermo-mechanical strain transfer, explicitly accounting for interfacial resistance, percolation-driven conductivity, fabrication-induced porosity, and strain-transfer efficiency. For randomly dispersed fillers, effective properties are predicted using coupled homogenization and percolation models. For engineered or oriented architectures, the framework directly integrates experimentally validated thermal and mechanical properties. Numerical results predict that at 5.8 vol%, graphene nanoplatelets can reduce the thermal response time by approximately 80% compared to a pure polymer coating, while silica nanoparticles are projected to extend the maximum operational temperature by approximately 27 K. Metallic fillers (Ag, Au) improve heat transfer but show limited high-temperature stability due to oxidation and interfacial resistance. The framework identifies optimal loading windows that balance thermal response time, mechanical integrity, and thermal durability. These findings provide practical, physics-based design guidelines for next-generation FBG sensors and establish the mechanistic foundation for adaptive, physics-informed Digital Twins tailored to aerospace, industrial, and biomedical applications.
- Open Access
- 24 September 2026
- Published by Elsevier in Materials Today Communications
- Vol. 56
Lifetime-aware design of adaptive piezoelectric micropillar composites under cyclic damage and frequency compensation
- 24 September 2026
- Published by Elsevier in Materials Today Communications
- Vol. 56
Open AccessLifetime-aware design of adaptive piezoelectric micropillar composites under cyclic damage and frequency compensation
- Open Access
- 6 September 2026
- Published by Springer Nature in Journal of Umm Al-Qura University for Applied Sciences
- p. 1-18
Nonlinear response of a microplate on soft visco-hyperelastic micropillar arrays under base excitation
Soft visco-hyperelastic micropillar arrays, elastomeric nanocomposites reinforced with graphene, MXene, or carbon nanotubes, provide tunable mechanical compliance essential for wearable sensors, soft robotics, and bio-integrated microdevices. Nevertheless, the nonlinear vibrational dynamics of rigid microstructures supported by such compliant foundations under operational base excitations remain poorly characterized, particularly when finite deformations activate strong geometric and material nonlinearities. This work develops a physics-based model that couples incompressible neo-Hookean hyperelasticity with Kelvin–Voigt viscoelasticity to capture large-strain dynamics of PDMS-based micropillar arrays supporting a metallic microplate under harmonic base excitation. Through Galerkin projection of the governing equation of motion, frequency–amplitude responses reveal four quantified design principles for engineering predictable dynamics: (i) nanofiller incorporation that raises the effective modulus from 0.4 to 1.5 MPa suppresses classical jump phenomena and reduces bifurcation interval lengths by up to 90%; (ii) enhanced viscoelastic damping attenuates resonance amplitudes by 45% while promoting linearized response; (iii) geometric tuning via pillar height increase (from $$\:5\:\mu\:m$$ to $$\:7\:\mu\:m$$ ) linearizes system dynamics and shrinks nonlinear intervals by 70%; and (iv) the static acceleration component elevates the effective natural frequency through pre-compression stiffening, whereas the harmonic component governs bifurcation onset. Notably, at the lowest modulus ( $$\:{E}_{m}=\:0.4\:MPa$$ ), softening permits sufficiently large deflections to activate nonlinearities, triggering a Neimark–Sacker bifurcation and quasiperiodic response, a regime absent in stiffer configurations. This identification is based on the characteristic frequency response signature where the periodic solution loses stability, consistent with the creation of an invariant torus as described in nonlinear dynamics theory. These principles establish a rational framework for designing soft-supported microsystems with predictable vibrational behavior under real-world excitations, a prerequisite for signal fidelity in next-generation wearable and implantable sensors.- 6 September 2026
- Published by Springer Nature in Journal of Umm Al-Qura University for Applied Sciences
- p. 1-18
Open AccessNonlinear response of a microplate on soft visco-hyperelastic micropillar arrays under base excitation
Soft visco-hyperelastic micropillar arrays, elastomeric nanocomposites reinforced with graphene, MXene, or carbon nanotubes, provide tunable mechanical compliance essential for wearable sensors, soft robotics, and bio-integrated microdevices. Nevertheless, the nonlinear vibrational dynamics of rigid microstructures supported by such compliant foundations under operational base excitations remain poorly characterized, particularly when finite deformations activate strong geometric and material nonlinearities. This work develops a physics-based model that couples incompressible neo-Hookean hyperelasticity with Kelvin–Voigt viscoelasticity to capture large-strain dynamics of PDMS-based micropillar arrays supporting a metallic microplate under harmonic base excitation. Through Galerkin projection of the governing equation of motion, frequency–amplitude responses reveal four quantified design principles for engineering predictable dynamics: (i) nanofiller incorporation that raises the effective modulus from 0.4 to 1.5 MPa suppresses classical jump phenomena and reduces bifurcation interval lengths by up to 90%; (ii) enhanced viscoelastic damping attenuates resonance amplitudes by 45% while promoting linearized response; (iii) geometric tuning via pillar height increase (from $$\:5\:\mu\:m$$ to $$\:7\:\mu\:m$$ ) linearizes system dynamics and shrinks nonlinear intervals by 70%; and (iv) the static acceleration component elevates the effective natural frequency through pre-compression stiffening, whereas the harmonic component governs bifurcation onset. Notably, at the lowest modulus ( $$\:{E}_{m}=\:0.4\:MPa$$ ), softening permits sufficiently large deflections to activate nonlinearities, triggering a Neimark–Sacker bifurcation and quasiperiodic response, a regime absent in stiffer configurations. This identification is based on the characteristic frequency response signature where the periodic solution loses stability, consistent with the creation of an invariant torus as described in nonlinear dynamics theory. These principles establish a rational framework for designing soft-supported microsystems with predictable vibrational behavior under real-world excitations, a prerequisite for signal fidelity in next-generation wearable and implantable sensors. - Open Access
- 4 June 2026
- Published by Elsevier in Thermal Science and Engineering Progress
- Vol. 75
Insights into experimental evaluation of the non-Fourier heat transfer model in biological tissues
- 4 June 2026
- Published by Elsevier in Thermal Science and Engineering Progress
- Vol. 75
Open AccessInsights into experimental evaluation of the non-Fourier heat transfer model in biological tissues
- Open Access
- 4 May 2026
- Published by Elsevier in International Journal of Heat and Mass Transfer
- Vol. 267
Innovative non-ablative dermatologic strategy: Impinging jet surface-protected multi-beam laser therapy with CNN-based parameter optimization
- 4 May 2026
- Published by Elsevier in International Journal of Heat and Mass Transfer
- Vol. 267
Open AccessInnovative non-ablative dermatologic strategy: Impinging jet surface-protected multi-beam laser therapy with CNN-based parameter optimization
- Open Access
- 19 March 2026
- Published by Elsevier in Results in Engineering
- Vol. 30
Enhanced sensitivity in capacitive micro-machined ultrasound transducers using hydrogel soft dielectric materials for implantable biomedical applications
- 19 March 2026
- Published by Elsevier in Results in Engineering
- Vol. 30
Open AccessEnhanced sensitivity in capacitive micro-machined ultrasound transducers using hydrogel soft dielectric materials for implantable biomedical applications
- 26 February 2026
- Published by Springer Nature in Journal of the Brazilian Society of Mechanical Sciences and Engineering
- Vol. 48 (3) , 235
High-sensitivity capacitive sensors with porous dielectrics: theory, simulation, and design framework
- 26 February 2026
- Published by Springer Nature in Journal of the Brazilian Society of Mechanical Sciences and Engineering
- Vol. 48 (3) , 235
High-sensitivity capacitive sensors with porous dielectrics: theory, simulation, and design framework
- Open Access
- 17 January 2026
- Published by Springer Nature in Journal of Umm Al-Qura University for Applied Sciences
- p. 1-24
Nonlinear mechanics and parametric sensitivity of a displacement-dependent soft porous PDMS-based rectangular capacitive sensor: instability analysis
In many micro-capacitive pressure sensors, electrostatic forces are weak at larger gaps but strengthen considerably as the gap narrows. Achieving smooth movement and displacement necessitates a low initial mechanical stiffness in the sensor structure. This study introduces a porous polydimethylsiloxane (PDMS) elastomeric filler, which exhibits displacement-dependent porosity, leading to an increase in stiffness with displacement, a characteristic distinct from traditional air-gap designs where stiffness remains constant. This paper investigates the static instability of a micro-capacitive rectangular plate (MCRP), a crucial component in capacitive pressure sensors. The MCRP is supported by a porous PDMS filler and subjected to external pressure and electrostatic bias actuation. A novel aspect of this research involves realistically modeling the PDMS filler’s behavior by establishing a power-law relationship between its Young’s modulus and porosity, which is essential for accurately predicting the sensor’s response.The MCRP is influenced by three primary forces: a downward measurement pressure, an upward mechanical pressure from the deflected PDMS filler, and a downward electrostatic pressure from the bias voltage. Utilizing nonlinear strain effects, the Airy stress function, and the Hamiltonian principle, we derive the governing coupled partial differential equations (PDEs) for static deflection, incorporating new terms that describe the PDMS filler’s behavior. These equations are then simplified using Galerkin’s method into a set of nonlinear algebraic equations and solved numerically. The sensitivity of the designed capacitive pressure sensor exhibits a remarkable increase when the porosity power index is below its critical value of $$\:{n}_{cr}\cong\:1.18$$ . Moreover, an increased power index value impacts sensitivity in two distinct ways. Firstly, it results in a reduction in the overall sensitivity of the sensor. Secondly, and conversely, it contributed to an expansion of the measurable pressure range. The finding can be beneficial for a variety of target applications as wearable electronics, health monitoring, robotics and human-machine interaction.- 17 January 2026
- Published by Springer Nature in Journal of Umm Al-Qura University for Applied Sciences
- p. 1-24
Open AccessNonlinear mechanics and parametric sensitivity of a displacement-dependent soft porous PDMS-based rectangular capacitive sensor: instability analysis
In many micro-capacitive pressure sensors, electrostatic forces are weak at larger gaps but strengthen considerably as the gap narrows. Achieving smooth movement and displacement necessitates a low initial mechanical stiffness in the sensor structure. This study introduces a porous polydimethylsiloxane (PDMS) elastomeric filler, which exhibits displacement-dependent porosity, leading to an increase in stiffness with displacement, a characteristic distinct from traditional air-gap designs where stiffness remains constant. This paper investigates the static instability of a micro-capacitive rectangular plate (MCRP), a crucial component in capacitive pressure sensors. The MCRP is supported by a porous PDMS filler and subjected to external pressure and electrostatic bias actuation. A novel aspect of this research involves realistically modeling the PDMS filler’s behavior by establishing a power-law relationship between its Young’s modulus and porosity, which is essential for accurately predicting the sensor’s response.The MCRP is influenced by three primary forces: a downward measurement pressure, an upward mechanical pressure from the deflected PDMS filler, and a downward electrostatic pressure from the bias voltage. Utilizing nonlinear strain effects, the Airy stress function, and the Hamiltonian principle, we derive the governing coupled partial differential equations (PDEs) for static deflection, incorporating new terms that describe the PDMS filler’s behavior. These equations are then simplified using Galerkin’s method into a set of nonlinear algebraic equations and solved numerically. The sensitivity of the designed capacitive pressure sensor exhibits a remarkable increase when the porosity power index is below its critical value of $$\:{n}_{cr}\cong\:1.18$$ . Moreover, an increased power index value impacts sensitivity in two distinct ways. Firstly, it results in a reduction in the overall sensitivity of the sensor. Secondly, and conversely, it contributed to an expansion of the measurable pressure range. The finding can be beneficial for a variety of target applications as wearable electronics, health monitoring, robotics and human-machine interaction.