Application Of High Electric Field Research Articles

Large pyroelectric energy conversion in lead scandium tantalate thin films

Non-linear pyroelectric energy harvesting using ferroelectric thin films exhibits high energy conversion, primarily due to their large breakdown field compared to bulks. Here, we report the pyroelectric energy conversion potential of lead scandium tantalate, Pb(Sc1/2Ta1/2)O3 (PST) thin film fabricated on a c-sapphire substrate using chemical solution deposition. To enable the application of high electric field and to assess the pyroelectric energy conversion performance, interdigitated electrodes were deposited on the PST thin film. A maximum harvested energy density of 9.1 J cm−3 per cycle was deduced from polarization measurements in films undergoing an Olsen cycle between 0 °C and 150 °C when the electric field was varied between 50 and 1500 kV/cm. Furthermore, PST thin films can reach up to 27 % of Carnot efficiency for a temperature interval of 10 K between 30 °C and 40 °C. This study highlights the significance of PST thin films for electro-thermal energy harvesting and promising opportunities for enhancing the conversion efficiency and power density using thin films or thin film multi-layer capacitors in the future for thermal energy harvesting.

Probing Electronic Band Structures of Dielectric Polymers via Pre-Breakdown Conduction.

The electronic band structure, especially the defect states at the conduction band tail, dominates electron transport and electrical degradation of a dielectric material under an extremely high electric field. However, the electronic band structure in a dielectric is barely well studied due to experimental challenges in detecting the electrical conduction to an extremely high electric field, i.e., prebreakdown. In this work, the electronic band structure of polymer dielectric films is probed through an in situ prebreakdown conduction measurement method in conjunction with a space-charge-limited-current spectroscopic analysis. An exponential distribution of defect states at the conduction band tail with varying trap levels is observed in accordance with the specific morphological disorder in the polymer dielectric, and the experimental defect states show also a favorable agreement with the calculated density of states from the density functional theory. The methodology demonstrated in this work bridges the molecule-structure-determined electronic band structure and the macro electrical conduction behavior with a highly improved understanding of material properties that control the electrical breakdown, and paves a way for guiding the modification of existing material and the exploration of novel materials for high electric field applications.

Enhancement and Function of the Piezoelectric Effect in Polymer Nanofibers.

ConspectusThe realization of intelligent, self-powered components and devices exploiting the piezoelectric effect at large scale might greatly contribute to improve our efficiency in using resources, albeit a profound redesign of the materials and architectures used in current electronic systems would be necessary. Piezoelectricity is a property of certain materials to generate an electrical bias in response to a mechanical deformation. This effect enables energy to be harvested from strain and vibration modes, and to sustain the power of actuators, transducers, and sensors in integrated networks, such as those necessary for the Internet of Thing. Polymers, combining structural flexibility with lightweight construction and ease of processing, have been largely used in this framework. In particular, the poly(vinylidene fluoride) [PVDF, (CH2CF2)n] and its copolymers exhibit strong piezoelectric response, are biocompatibile, can endure large strains and can be easily shaped in the form of nanomaterials. Confined geometries, improving crystal orientation and enhancing piezoelectricity enable the fabrication of piezoelectric nanogenerators, which satisfy many important technological requirements, such as conformability, cheap fabrication, self-powering, and operation with low-frequency mechanical inputs (Hz scale). This account reports on piezoelectric polymer nanofibers made by electrospinning. This technique enables the formation of high-aspect-ratio filaments, such as nanowires and nanofibers, through the application of high electric fields (i.e., on the order of hundreds of kV/m) and stretching forces to a polymeric solution. The solution might be charged with functional, organic or inorganic, fillers or dopants. The solution is then fed at a controlled flow rate through a metallic spinneret or forms a bath volume, from which nanofibers are delivered. Fibers are then collected onto metallic surfaces, and upon a change of the collecting geometry, they can form nonwovens, controlled arrays, or isolated features. Nanofibers show unique features, which include their versatility in terms of achievable chemical composition and chemico-physical properties. In addition, electrospinning can be up-scaled for industrial production. Insight into the energy generation mechanism and how the interaction among fibers can be used to enhance the piezoelectric performance are given in this paper, followed by an overview of fiber networks as the active layer in different device geometries for sensing, monitoring, and signal recognition. The use of biodegradable polymers, both natural and synthetic, as critically important building blocks of the roadmap for next-generation piezoelectric devices, is also discussed, with some representative examples. In particular, biodegradable materials have been utilized for applications related to life science, such as the realization of active scaffolds and of electronic devices to be placed in intimate contact with living tissues and organs. Overall, these materials show many relevant properties that can be of very high importance for building next-generation, sustainable energy harvesting, self-rechargeable devices and electronic components, for use in several different fields.

(Digital Presentation) Calculation of the Energy Band Diagram and Estimation of Electronic Transport Parameters of Metastable Amorphous Ge2Sb2Te5

Phase change memory (PCM) is a high speed, high density non-volatile resistive memory technology that utilizes different phases (crystalline and amorphous) of phase change materials such as Ge2Sb2Te5 (GST) to store information [1]. Here, the material undergoes two types of reversible switching phenomena: (i) Ovonic Threshold Switching (OTS), which causes the amorphous phase of the material to switch from a highly resistive state to conductive state with application of high electric fields, resulting in current flow and (ii) Ovonic Memory Switching (OMS), which is due to the change of the phase of the material between amorphous and crystalline phases induced by heating [2]. Even though PCM entered high volume manufacturing, the electronic properties of the phase change materials are still not well understood [3,4]. In this work, we construct the energy band diagram of amorphous GST as a function of temperature using a temperature dependent model of effective activation energy of conduction in metastable amorphous GST [5], which we obtained from high-speed experiments on GST line-cells [6]. Assuming the bandgap energy to linearly decrease with temperature [7,8] and p-type conduction (based on positive Seebeck coefficients measured in a wide temperature range [9]) , we determine a temperature dependent Fermi energy level from 0K to melting temperature, Tmelt ~ 858 K. Liquid GST is expected to become metallic (bandgap collapsing to 0) at ~ 894K, based on the experimental results. We also estimate the carrier concentration at Tmelt utilizing the latent heat of fusion (126 kJ/kg) [10] to be pmelt = 1.47 x 1022 cm-3. Using the melt resistivity measured on GST thin film, we calculate the carrier mobility at melting point as µmelt ~0.187 cm2/V-s, close to the previously reported value of 0.15 cm2/V-s based on crystalline state mobility and a density of states calculation [2]. Assuming a weak temperature dependence of the mobility [5], we obtain the carrier concentration of ~3.37× 1017 cm-3 at room temperature which lies within the ~1017-1018 cm-3 range estimated in a former study [3]. Finally, we calculate conduction activation energy of as-deposited amorphous GST from temperature dependent Seebeck coefficient measured simultaneously with the resistance [9]. The activation energy varies as a parabolic function of temperature where it starts from 0 eV at 0 K, reaches a peak of ~0.257 eV near glass transition temperature (~400 K) with the room temperature value of ~0.24 eV and becomes 0 eV again at ~810 K. We also utilize the Seebeck coefficient measurements along with the band edges and Fermi energy level information from the energy band diagram to calculate the ratio of minority carrier concentration to the total carrier concentration as a function of temperature; this is useful to predict the temperature beyond which bipolar conduction becomes significant.Acknowledgment: Analysis is performed with the support of US National Science Foundation (NSF) award ECCS 1711626. The experimental data used for this analysis were collected with the support of US NSF DMR-1710468 on devices fabricated with the support of US Department of Energy Office of Basic Energy Sciences.

Structural and electrical response of poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) copolymer free‐ standing films

AbstractPoly(vinylidene fluoride) (PVDF) based polymers were studied as potential dielectric candidates for polymer film capacitors. The present work focused on the structural and electrical responses of PVDF homopolymer and P(VDF‐CTFE) copolymers (CTFE, chlorotrifluoroethylene). The solvent casting technique was used for the fabrication of free‐standing polymer films. PVDF and P(VDF‐CTFE) copolymer films with different CTFE content were cast under different processing conditions. The structural response of these semicrystalline polymer films showed the existence of crystalline phases and changes in crystallinity depending upon the preparation conditions and CTFE content. The electrical responses of PVDF and P(VDF‐CTFE) copolymers were investigated under the application of low and high electric fields. For the dielectric study, temperature‐dependent dielectric measurements at different frequencies were assessed. Dielectric relaxation in the vicinity of the glass transition temperature was observed along with quantification of activation energies. The effect of CTFE content is also presented. Features such as interface polarization was observed in the high temperature regime. Furthermore, room temperature polarization versus electric field loops of PVDF and P(VDF‐CTFE) copolymers were measured at frequency values of 400 and 10 Hz. All PVDF and P(VDF‐CTFE) copolymers at low frequency showed lossy capacitor behavior which was further investigated by measuring polarization versus electric field loop over a wide range of frequencies, i.e. 0.1–400 Hz. Polarization values of PVDF and P(VDF‐CTFE) copolymer films with different CTFE content were compared on the bases of local dipole moments. © 2022 Society of Industrial Chemistry.

Enhancing soil vapor extraction with EKSF for the removal of HCHs

This paper evaluates the combination of electrokinetic soil flushing (EKSF) with soil vapor extraction (SVE) for the removal of four hexachlorocyclohexane (HCH) isomers contained in a real matrix. Results demonstrate that the combination of EKSF and SVE can be positive, but it is required the application of high electric fields (3 V cm−1) in order to promote a higher temperature in the system, which improves the volatilization of the HCH contained in the system. Electrokinetic transport is also enhanced with the application of higher electric gradients, but these transport processes are slower than the volatilization processes, which are the primary in this system. Hence collection of species in the electrolyte wells is negligible as compared to the compound dragged with air by the SVE but the temperature increase demonstrates a good performance. Combination of EKSF with SVE can efficiently exhaust the four HCH isomers reaching a removal of more than 90% after 15 days of treatment (20% more than values attained by SVE) but it is required the application of high electric fields to promote a higher temperature in the system (to improve the volatilization) and EK transport (to improve the dragging). 1-D transport model can be easily used to estimate the average pore water velocity and the effective diffusion of each compound under the different experimental conditions tested.

Finite Element Model for Investigating the Thermo-Electro-Mechanical Response of Inhomogeneously Deforming Dielectric Elastomer Actuators

Among the available soft active materials, Dielectric elastomers (DEs) possess the capability of achieving the large actuation strain under the application of high electric field. The material behavior of such elastomers is affected significantly by the change in temperature. This paper reports a 3-D finite element framework based on the coupled nonlinear theory of thermo-electro-elasticity for investigating the thermal effects on the electromechanical performance of inhomogeneously deforming dielectric elastomer actuators (DEAs). The material behavior of the actuator is modeled using the neo-Hookean model of hyperelasticity with temperature dependent shear modulus. An in-house computational code is developed to implement the coupled finite element framework. Firstly, the accuracy of the developed FE code is verified by simulating the temperature effects on the actuation response and pull-in instability of the benchmark homogeneously deforming planar DE actuator. Further, the influence of temperature on the electromechanical responses of complex bi-layered bending actuator and buckling pump actuator involving inhomogeneous deformation is investigated. The numerical framework and the associated inferences can find their potential use in addressing the effect of temperature in the design of electro-active polymer based actuators.

Mechanism of Spontaneous Surface Modifications on Polycrystalline Cu Due to Electric Fields.

We present a credible mechanism of spontaneous field emitter formation in high electric field applications, such as Compact Linear Collider in CERN (The European Organization for Nuclear Research). Discovery of such phenomena opens new pathway to tame the highly destructive and performance limiting vacuum breakdown phenomena. Vacuum breakdowns in particle accelerators and other devices operating at high electric fields is a common problem in the operation of these devices. It has been proposed that the onset of vacuum breakdowns is associated with appearance of surface protrusions while the device is in operation under high electric field. Moreover, the breakdown tolerance of an electrode material was correlated with the type of lattice structure of the material. Although biased diffusion under field has been shown to cause growth of significantly field-enhancing tips starting from initial nm-size protrusions, the mechanisms and the dynamics of the growth of the latter have not been studied yet. In the current paper we conduct molecular dynamics simulations of nanocrystalline copper surfaces and show the possibility of protrusion growth under the stress exerted on the surface by an applied electrostatic field. We show the importance of grain boundaries on the protrusion formation and establish a linear relationship between the necessary electrostatic stress for protrusion formation and the temperature of the system. Finally, we show that the time for protrusion formation decreases with the applied electrostatic stress, we give the Arrhenius extrapolation to the case of lower fields, and we present a general discussion of the protrusion formation mechanisms in the case of polycrystalline copper surfaces.

Design of alginate based micro‐gels via electro fluid dynamics to construct microphysiological cell culture systems

AbstractIn the last decade, different technological approaches have been proposed for the fabrication of micro‐gels as cell carriers to investigate in vitro response. Among them, electro fluid dynamic atomization (EFDAs) is emerging as a highly versatile process that allows atomizing polymer solutions at the micrometric size scale by the application of high voltage electric field. Here, we propose to revisit the process configuration to optimize the fabrication of sodium alginate micro‐gels with different physical and mechanical properties and validate their use for in vitro culture with human mesenchymal stem cells (hMSCs). By optical microscopy, we explored the strict correlation between particle morphology and process parameters, that is, voltage, flow rate, electrode gap and needle diameter. Meanwhile, by scanning electron microscopy and atomic force microscopy, we investigated basic differences in terms of physical (i.e., swelling) and mechanical properties (i.e., stiffness), ascribable to alginates solutions with different concentrations. Lastly, in vitro tests confirmed the effect of physical properties of microgels on the biological response of hMSCs cultured onto the surface. In perspective, the integration of alginate with peculiar extracellular matrix (ECM) components (i.e., proteins, mineral phase) may contribute to assign specific biological functionalities to the microgels in order to reproduce 3D models to investigate in vivo‐like behavior of cells.

Effect of dc voltage pulsing on high-vacuum electrical breakdowns near Cu surfaces

Vacuum electrical breakdowns, also known as vacuum arcs, are a limiting factor in many devices that are based on application of high electric fields near their component surfaces. Understanding of processes that lead to breakdown events may help mitigating their appearance and suggest ways for improving operational efficiency of power-consuming devices. Stability of surface performance at a given value of the electric field is affected by the conditioning state, i.e. how long the surface was exposed to this field. Hence, optimization of the surface conditioning procedure can significantly speed up the preparatory steps for high-voltage applications. In this article, we use pulsed dc systems to optimize the surface conditioning procedure of copper electrodes, focusing on the effects of voltage recovery after breakdowns, variable repetition rates as well as long waiting times between pulsing runs. Despite the differences in the experimental scales, ranging from $10^{-4}$ s between pulses, up to pulsing breaks of $10^5$ s, the experiments show that the longer the idle time between the pulses, the more probable it is that the next pulse produces a breakdown. We also notice that secondary breakdowns, i.e. those which correlate with the previous ones, take place mainly during the voltage recovery stage. We link these events with deposition of residual atoms from vacuum on the electrode surfaces. Minimizing the number of pauses during the voltage recovery stage reduces power losses due to secondary breakdown events improving efficiency of the surface conditioning.

Crystallographic design for energy storage.

A crystallographic brick wall design for polycrystalline dielectric ceramics now allows the application of high electric fields at minimal misfit strain, yielding supreme reliability and high energy density.

Electrode interface polarization formation in dielectric elastomer actuators

Dielectric elastomer actuators (DEAs) are a class of electrostatic actuators that have promising applications in fields like sensors, soft-robotics, microfluidics, and energy harvesting. The crucial points in the working principle of DEA are the application of high electric field and the use of compliant electrodes. These electrodes are typically composed of a mixture of a soft polymer base filled with highly conductive particles. In this work, we show that the charged impurities, possibly present in the electrodes composite, in combination with a high electric field can cause the formation of polarization interface layers between the electrodes and the inner dielectric. These layers can, in the long term, diminish the actuation performance of the DEA.

Comparative analysis of metal diffusion effects in polymer films coated with spin coating and floating film transfer techniques

In this work a comparative analysis between the extent of gold diffusion of the top coated gold layer into the conducting polymer matrix of spin coated polymer films and polymer films coated via floating film transfer method (FTM) has been investigated. For the sake of comparison two different device configurations i.e. ITO/rr-P3HT (spin coated)/Au and ITO/rr-P3HT (spin coated)/rr-P3HT (FTM coated)/Au have been compared. The J-V characteristics of these devices revealed a non-Ohmic injection occurring near the top gold electrode/polymer interface. Furthermore, the current flowing through the device consisting of FTM layer/Au interface was observed to be lower as compared to the one consisting of spin coated layer/Au interface, indicating higher gold diffusion in well-ordered FTM thin films. These observations have been validated by optical and structural characterization methods viz. absorption, photoluminescence, Raman spectroscopy and X-Ray Diffraction (XRD) measurement. Finally Fowler-Nordheim (FN) tunneling currents were studied under high electric field applications for the two devices which confirmed presence of higher barrier at the interface of gold and FTM coated polymer film.

Properties of PVDF films stretched in machine direction

Polyvinylidene fluoride (PVDF) films possess superior piezoelectric properties due to the β-phase obtained by methods, such as addition of nanofillers, application of high electric field, use of polar solvents and mechanical stretching. Simultaneous stretching and heating of the films can reduce porosity, increase transformation from α-phase to β-phase, and hence, improve their piezoelectric properties. This article presents the effects of stretching PVDF films on the β-phase formation and the resulting mechanical properties. A custom-designed stretching unit with roller mechanism and heating provision was employed for the purpose. The 200% stretched films at 100°C showed 86.79% β-phase, which is in correlation with X-ray diffraction peaks at 2 θ = 20.3–20.6°. Transmission electron microscopy and scanning electron microscopy of the stretched films revealed spherulitic to lamellar transformation and decrease in porosity. Stretching increased crystallinity from 32.99% to 44.84%. Nanoindentation results showed increase in hardness and Young’s modulus from 23.33 MPa to 93.3 MPa and 0.483 GPa to 1.816 GPa, respectively. Tensile strength increased from 4.72 MPa to 21.02 MPa. The experiments were conducted using L9 orthogonal array and the results were analyzed using analysis of variance and gray relational analysis.

Method for identifying ageing in epoxy‐mica composite insulation used in rotational machines through modelling of dielectric relaxation

Dielectric response analysis, performed in time domain and frequency domain is one of the interesting methods used for condition assessment of high voltage equipment. In this article, the degradation of epoxy-mica composite insulation which is widely used in rotating machines has been investigated through frequency domain spectroscopy measurements. Artificial ageing of the carefully prepared stator bar insulation sample was performed through simultaneous application of high temperature and electric field in a designated environmental chamber for specific durations. To study the effect of temperature, the measurements were performed at temperatures ranging from 20 to 60°C at different ageing status. Following experimental work, the measurement results were modelled using Havriliak–Negami model and ageing sensitive parameters were extracted. To study the effect of temperature, the measurements were performed at temperatures ranging from 20 to 60°C. The modelled results matched well with the experimental measurements and certain model parameters sensitive to the ageing condition were identified. The numerical relationships between the insulation status of the stator bar and the aforementioned parameters were identified. It was observed that the nature of the numerical relationship remains identical in the investigated temperature range, although the coefficients vary to some extent.

From Peripheral Proteins to Membrane Motors - Mass Spectrometry Comes of Age

What can we learn from the study of a protein complex in the gas phase of the mass spectrometer? Aside from the compositional information that is available from obtaining the molecular mass of an intact protein complex, many additional properties can be deduced: these include polydispersity and heterogeneity, which are some of most challenging properties of protein complexes, making them almost impossible to study by conventional structural biology approaches. Mass spectrometry is providing significant insight into protein composition within assemblies by uncovering the effects of post-translational modifications, the dynamics of subunit exchange and changes in interactions in response to small molecule binding. Recent breakthroughs, which combine the study of intact membrane complexes with knowledge of lipid binding sites, is informing both the oligomerisation and downstream coupling of GPCRs. While the majority of these studies of membrane proteins have been performed in detergent micelles very recently we have successfully employed a new means of ionizing proteins directly from membranes. Following sonication of lipid vesicles and application of high electric fields, proteins are effectively drawn out of their native membrane locations into the gas phase of the mass spectrometer. This new approach is revealing many new interactions that have been lost following disruption in detergent micelles.

Structure stability of few-layer graphene under high electric field

The stability of material structure is the key factor to determine its service capacity and lifetime. The structure evolution of vertical few-layer graphene (FLG) under high electric field was directly observed in situ TEM. The structure stability of FLG depends on its crystallinity and edge morphology. The vertical FLG without pinhole defects can sustain an electrostatic field beyond 58.5 V/nm. The vertical FLG with pinhole defects disintegrated from top to bottom due to field evaporation and the critical electrostatic field weaken to 17.4 V/nm. The vertical FLG with curly layer perpendicular to the electric field stretched and slid at the edge due to the layer sliding and the critical fracture electrostatic field of it was low to 7.5 V/nm which is an order of magnitudes small than that of the curly layer parallel to the electrostatic field of 24.7 V/nm. Those results were the first direct observation of the nano-structure evolution of FLG under high electric field. It helps to understand the deterioration mechanism of FLG under high electric field in free space and provides guidance for the high electric field applications such as field electron emitter and scanning tunneling microscopy.

High- k Polymer Nanocomposites Filled with Hyperbranched Phthalocyanine-Coated BaTiO3 for High-Temperature and Elevated Field Applications.

Two sets of thermal stable nanocomposites were fabricated by using engineering plastics poly(ether sulfone) (PES) as a matrix and phthalocyanine molecules (CuPc) or hyperbranched phthalocyanine (HCuPc)-coated barium titanate (BT) nanoparticles as fillers for high electric field and high-temperature dielectric applications. By side-by-side comparison, the hyperbranched coating is finely addressed for enhancing the dielectric response and breakdown strength of the composites. Specifically, BT-HCuPc/PES exhibits 40% lower dielectric loss and about 110% larger breakdown strength than BT-CuPc/PES. The addition of hyperbranched phthalocyanine may enhance the compatibility and dispersion of the ceramic fillers in the polymer matrix and reduces the charge carrier between the filler and matrix. Meanwhile, high dielectric constant, high breakdown, and low dielectric loss are well-maintained in the composites filled with hyperbranched phthalocyanine-modified BT from room temperature to 150 °C. The discharged energy density of the composites (20 vol % BT-HCuPc/PES) can reach 2.0 J/cm3 at 300 MV/m, about 166% of that of the polymer matrix (1.2 J/cm3). Our findings on hyperbranched coating structure could be applicable to other ceramic-polymer composites to enhance their dielectric response.

Leakage Current Degradation Due to Ion Drift and Diffusion in Tantalum and Niobium Oxide Capacitors

AbstractHigh temperature and high electric field applications in tantalum and niobium capacitors are limited by the mechanism of ion migration and field crystallization in a tantalum or niobium pentoxide insulating layer. The study of leakage current (DCL) variation in time as a result of increasing temperature and electric field might provide information about the physical mechanism of degradation. The experiments were performed on tantalum and niobium oxide capacitors at temperatures of about 125°C and applied voltages ranging up to rated voltages of 35 V and 16 V for tantalum and niobium oxide capacitors, respectively. Homogeneous distribution of oxygen vacancies acting as positive ions within the pentoxide layer was assumed before the experiments. DCL vs. time characteristics at a fixed temperature have several phases. At the beginning of ageing the DCL increases exponentially with time. In this period ions in the insulating layer are being moved in the electric field by drift only. Due to that the concentration of ions near the cathode increases producing a positively charged region near the cathode. The electric field near the cathode increases and the potential barrier between the cathode and insulating layer decreases which results in increasing DCL. However, redistribution of positive ions in the insulator layer leads to creation of a ion concentration gradient which results in a gradual increase of the ion diffusion current in the direction opposite to the ion drift current component. The equilibrium between the two for a given temperature and electric field results in saturation of the leakage current value. DCL vs. time characteristics are described by the exponential stretched law. We found that during the initial part of ageing an exponent n = 1 applies. That corresponds to the ion drift motion only. After long-time application of the electric field at a high temperature the DCL vs. time characteristics are described by the exponential stretched law with an exponent n = 0.5. Here, the equilibrium between the ion drift and diffusion is achieved. The process of leakage current degradation is therefore partially reversible. When the external electric field is lowered, or the samples are shortened, the leakage current for a given voltage decreases with time and the DCL vs. time characteristics are described by the exponential stretched law with an exponent n = 0.5, thus the ion redistribution by diffusion becomes dominant.

Comparison of direct electrocaloric characterization methods exemplified by 0.92 Pb(Mg1/3Nb2/3)O3‐0.08 PbTiO3 multilayer ceramics

AbstractElectrocaloric device structures have been developed as multilayer ceramics (MLCs) based on fundamental research carried out on PMN‐8PT bulk ceramics. Two different MLC structures were prepared with nine layers each and layer thicknesses of 86 μm and 39 μm. The influence of the device design on its properties has been characterized by microstructural, dielectric, ferroelectric, and direct electrocaloric measurement. For direct characterization two different methods, ie temperature reading (thermistor and thermocouple) and heat flow measurement (differential scanning calorimetry), were used. A comparison of results revealed a highly satisfactory agreement between the different methods. This study confirms that MLCs are promising candidates for implementation into energy‐efficient electrocaloric cooling systems providing large refrigerant volume and high electrocaloric effect. Due to their micron‐sized active layers, they allow for the application of high electric fields under low operation voltages. We measured a maximum electrocaloric temperature change of ΔT=2.67 K under application/withdrawal of an electric field of ΔE=16 kV mm−1, which corresponds to operation voltages below 1.5 kV.