Photo-pyroelectric effect in piezoelectric polymer composites: An innovative pathway for advanced technologies

The performance of the 0–3 piezoelectric composite consisting of two piezoelectric materials (PZT5H and PVDF) is analyzed to improve the piezoelectric properties for sensing applications using FEA and validated with the experimental and analytical results. The experimental and predicted results are showing good matches. The average piezoelectric coefficient d33 of the piezoelectric composite and the effective elastic, dielectric and piezoelectric properties of the 0–3 passive matrix piezoelectric composite were determined from the unit cell model. It is observed from the analysis that the performance of 0–3 piezo-composite has excellent piezoelectric properties and also optimized unit cell size and polymer matrix.

In this study, epoxy based piezoelectric polymer composites were fabricated using two different curing agents and varying compositions of poly(vinylidene) fluoride (PVDF), barium titanate (BaTiO 3 ), and conductive silver nanoparticles. The effect of piezoelectric ceramic and conductive nanofillers on enhancing the PVDF β phase within the composite structure was investigated. Structural, thermal, and morphological characterizations of the polymer composites were performed using x‐ray diffraction, differential scanning calorimetry, and scanning electron microscopy. Furthermore, a comprehensive analysis of mechanical properties and fracture toughness was conducted in addition to the piezoelectric behavior. A voltage output of 1.35 V was generated by a polymer composite containing 20 wt% BaTiO 3 , with a Young's modulus of 2 GPa and a fracture energy of 2.3 kJ/m 2 . The findings of this study contribute to expanding the knowledge and understanding of piezoelectric polymer composites, enabling their potential utilization in various scientific and technological applications. Highlights Enhancing mechanical and piezoelectric properties of epoxy based piezoelectric composites. A clear and comprehensive description of the experimental procedures employed. Comparative analysis methods: structural, thermal, mechanical, fracture, and piezoelectric property analyses.

Evaluation of effective properties of piezoelectric hybrid composites containing carbon nanotubes

In the paper entitled "Characterization of 1-3 piezoelectric polymer composites - a numerical and analytical evaluation procedure for thickness mode vibrations", the dependence of the thickness electromechanical coupling coefficient on the aspect ratio of piezoceramic fibers is studied by finite element simulation for various volume fractions of piezoceramic fibers in a 1-3 composite. The accuracy of the results is questionable because the boundary condition claiming that `predefined displacements are applied perpendicularly on $C^+$ plane on all nodes' is not suitable for the analysis of 1-3 composite with comparatively large aspect ratio from 0.2 to 1. A discussion regarding this problem and the suggested corrections are presented in this paper.

Biomedical transducers widely employ piezoceramic polymer composites with 1-3 connectivity. The research is aimed at determining the effective material properties of these composites in the micrometer scale by simulation. Volume fraction of piezoceramic in the composite plays an important role in composite material properties as studied by several researchers. It is also noted that the ber aspect ratio (a=l) also affects the composite material properties. Therefore it is intended to determine the effective material properties both analytically and by simulation using computer simulation software program ANSYS which implements nite element method (FEM). In the present work piezoelectric ber composites are modeled, analyzed and then the results are veried by using analytical equations. Important conclusions are drawn to select the piezocomposite materials for transducer applications.

A novel breathable piezoelectric membrane has been developed by growing zinc oxide (ZnO) nanorods on the surface of electrospun poly(vinylidene fluoride) (PVDF) nanofibers using a low-temperature hydrothermal method. Significant improvement in the piezoelectric response of the PVDF membrane was achieved without compromising breathability and flexibility. PVDF is one of the most frequently used piezoelectric polymers due to its high durability and reasonable piezoelectric coefficient values. However, further enhancement of its piezoelectric response is highly desirable for sensor and energy-harvester applications. Previous studies have demonstrated that piezoelectric ceramic and polymer composites can have remarkable piezoelectric properties and flexibility. However, devices made of such composites lack breathability and some present health risks in wearable applications for containing heavy metals. Unlike other piezoelectric ceramics, ZnO is non-toxic material and has been widely used in many applications including cosmetics. The fabrication of ZnO@PVDF porous electrospun membrane involves a simple low-temperature ZnO growth in aqueous solution, which does not weaken the polarization of PVDF created during electrospinning in the high electric field.

A finite element–based code was developed to capture the effect of particle shape on the electromechanical properties of three typical piezoelectric polymer composites. The electrical energy density and electric displacement distribution patterns were modeled by putting particles with different shapes into the model. To evaluate the reliability of investigations, differential equations were solved using Mori–Tanaka and finite element methodologies, where model predictions were appropriately consistent with each other regardless of particle shape and volume fraction of minor phase. Polymer composites filled with continuous fiber revealed similar electromechanical features irrespective of the piezoelectric nature of polymers. On the other hand, strain- and stress-induced electrical displacement distributions were sensitive to particle shape. The results suggest that densities corresponding to relative strain energy and relative electrical energy of composites containing continuous fiber inclusions are both higher than the analogous values obtained for the systems filled with short fiber and spherical particles. Likewise, the polymer composite with continuous fiber revealed improved electric displacement distribution compared to those filled with the other two types of filler. The truthfulness of the developed model was further ensured by placing multifarious particles into the host polymers, which is of vital importance from application point of view.

A high performance nanocellulose-PVDF based piezoelectric nanogenerator based on the highly active CNF@ZnO via electrospinning technology

Advances in virtual health monitoring, robotics, internet of things (IoT), and other emerging applications drive the technological improvements in flexible electronics and smart materials capable of sensing and energy harvesting. Lead-free piezoelectric polymer composites will be the materials of choice in these emerging applications due to their improved performance, non-toxic components, mechanical flexibility, light weight, processibility, and ease of integration into devices. Additionally these materials provide the potential to be self-powered, which might reduce or eliminate the need for batteries in certain devices.In this article, researchers from SABIC, a leading global chemical company and material solution provider, present an overview of their novel, high performing piezoelectric polymer composites developed using elastomeric polymers in combination with lead-free piezo ceramic additives. These novel composites show improved force sensitivity and temperature stability when compared to commercially available piezoelectric polymers. These property improvements open up new application spaces for flexible piezoelectric devices such as smart gloves, shoes, health monitoring patch, key pads, and haptic feedback.

The constitutive equations, of piezoelectric polymer composite materials used for their electromechanical characterisation are complicated and their analytical solution is difficult. Earlier models assumed either stress or strain components to be constant. In this paper we present a model for electromechanical characterisation of piezoceramic polymer composites. The assumptions are (i) the samples have complete stress free boundary conditions at the polymer piezoelectric interfaces, (ii) the materials are lossless, (iii) the co-ordinate axes are pure mode propagation directions and (iv) the electric potential and the displacements are assumed to be independent degrees of freedom. Based on these assumptions, expressions for impedance, phase velocities and electromechanical coupling constant are developed for piezoelectric polymer composites.

Lightweight flexible piezoelectric polymers are demanded for various applications. However, the low instinctively piezoelectric coefficient (i.e. d33) and complex poling process greatly resist their applications. Herein, we show that introducing dynamic pressure during fabrication is capable for poling polyvinylidene difluoride/barium titanate (PVDF/BTO) composites with d33 of ~51.20 pC/N at low density of ~0.64 g/cm3. The melt-state dynamic pressure driven energy implantation induces structure evolutions of both PVDF and BTO are demonstrated as reasons for self-poling. Then, the porous material is employed as pressure sensor with a high output of ~20.0 V and sensitivity of ~132.87 mV/kPa. Besides, the energy harvesting experiment suggests power density of ~58.7 mW/m2 can be achieved for 10 N pressure with a long-term durability. In summary, we not only provide a high performance lightweight, flexible piezoelectric polymer composite towards sustainable self-powered sensing and energy harvesting, but also pave an avenue for electrical-free fabrication of piezoelectric polymers.

3D printed 0–3 type piezoelectric composites with high voltage sensitivity

Piezoelectric polymer composites, particularly polyvinylidene fluoride (PVDF) blended with barium titanate (BT), show promise for wearable technologies as both energy harvesters and haptic actuators. However, these composites typically exhibit limited electromechanical coupling and insufficient β-phase formation. This study presents a novel approach using ionic liquids (ILs) to enhance PVDF-based piezoelectric composite performance. Through solution-casting methods, we examined the effect of IL concentration on the structural, mechanical, and piezoelectric properties of PVDF/BT composites. Results demonstrate that the use of IL significantly improves β-phase crystallization in PVDF while enhancing electrical properties and mechanical flexibility, which are key requirements for effective energy harvesting and haptic feedback applications. The optimized composites show a 25% increase in β-phase content, enhanced flexibility, and a 100% improvement in piezoelectric voltage output compared to other more conventional PVDF/BT systems. The IL-modified composite exhibits superior piezoelectric response, generating an output voltage of 9 V and an output power of 40.1 µW under mechanical excitation and a displacement of 138 nm when subjected to 13 V peak-to-peak voltage, making it particularly suitable for haptic interfaces. These findings establish a pathway toward high-performance, flexible piezoelectric materials for multifunctional wearable applications in human–machine interfaces.

Valveless micropumps are extensively used in micro fluidic systems, including health care monitoring and diagnostic devices, computer devices, and so on, as it forms the critical component in the microsystem for precise and controlled fluid handling. This paper proposes the design and development of a novel, significantly low cost, planar micropump with piezoelectric polymer composite, consisting of lead zirconate titanate and polyvinylidene fluoride, for actuation. The novelty lies in the synthesis and use of the piezoelectric polymer composite as the actuating mechanism and the diffuser/nozzle design around the line of appreciable stall to achieve maximum flow rate for the given boundary conditions. The parametric study on the micropump geometry, including, chamber depth and diameter as well as diffuser/nozzle was carried out by using numerical simulations in COMSOL multiphysics, to analyze the fluid flow rate. The response of piezoelectric polymer to the applied sinusoidal voltage causes flow rectification in the micropump. An aspect ratio (diffuser length/diffuser width) of 15 produces maximum fluid flow rate. The designed micropump can achieve maximum fluid flow rate at low applied voltage and frequency of operation. [2018-0166]

Appropriate technological solutions to healthcare can cause huge impact on medical processes and practices leading to sustainable future. Prevalence of diabetes and other chronic diseases has been steadily increasing for which self-attention and healthcare procedure is a logical solution. This paper proposes a piezoelectric polymer composite based micropump that is biocompatible and inexpensive. Lead Zirconate Titanate (PZT) powder is dispersed in polyvinyledene difluoride (PVDF) to form a novel PZT/PVDF composite material. The PZT/PVDF composite material is sonicated, cast, and cured to form a film which is used as the actuator. The polydimethylsiloxane (PDMS) based micropump is designed and fabricated using soft lithography technique. Once the master mold is prepared in clean room, other fabrication steps can be accomplished in a normal environment and multiple PDMS replicas can be prepared with ease. The proposed processing and fabrication steps are simple and inexpensive leading to substantial reduction in the device cost. The piezoelectric polymer based valveless micropump thus fabricated is subjected to performance testing. The micropump is found to deliver fluid in small quantities in a controlled manner and sufficient back pressure and flow rate can be achieved at low applied voltage and frequency.