High energy density dielectric capacitor films

Abstract

Embodiments of a dielectric film, a polymer electronic component, and a method of preparing a dielectric film are provided. The dielectric film includes an elastomeric or composite insulating polymer having a thickness of 1 μm or less and a dielectric breakdown strength of at least 10,000 kV / cm. The polymer electronic component includes a first electrode, a second electrode, and the dielectric film as described in which the dielectric film is disposed between the first electrode and the second electrode.

Description

HIGH ENERGY DENSITY DIELECTRIC CAPACITOR FILMSCROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This patent application claims the benefit of U.S. Provisional Patent Application No. 63 / 750,139, filed January 27, 2025, and to U.S. Provisional Patent Application No. 63 / 946.896, filed December 22, 2025, the entire teachings and disclosure of each of which are incorporated herein in their entireties by reference thereto.FIELD OF THE INVENTION

[0002] This invention generally relates to polymer films and, in particular, to polymer films having both high dielectric breakdown strength and dielectric constant.BACKGROUND OF THE INVENTION

[0003] Polymers have demonstrated immense potential across various applications, particularly in electronics and energy storage, where their versatility and safety under high electric fields make them a preferred choice over ceramics due to their ability to fail gracefully under extreme conditions. Among these, polymer dielectric materials are critical for capacitors, transistors, photovoltaic devices, and electrical insulation, owing to their dielectric properties, dielectric constant or permittivity (s'), dielectric breakdow n strength (EBD), and dielectric loss (s"). The demand for energy storage devices necessitates materials with high dielectric constant (s') and breakdown strength (EBD). as these properties directly influence the energy density (Ue) of dielectrics, as described by the equation:Ue= - £QE'EBD.

[0004] where so is vacuum permittivity, s' is the dielectric constant, and EBD is the maximum electric field a material can endure without degradation. A high s' ensures greater polarization, while a large EBD contributes to an even greater energy' storage, safety and efficiency under high-field conditions. Conversely, minimizing dielectric loss (s") reduces heat dissipation, enhancing the power cycling efficiency necessary for applications like electric vehicles.160273295

[0005] Polymers also offer advantages in manufacturability, scalability, and integration into compact or flexible designs compared to ceramics. However, they generally face challenges such as lower dielectric constant, thermal stability and mechanical durability7, especially in high-power and high-frequency applications. Structural features like polymer chain conformation significantly influence these properties. Flexible chains promote dipole alignment, enhancing permittivity7, while rigid or conjugated chains, such as those in polyimides, reduce dipole mobility but improve EBD by resisting deformation and charge transport under electric fields. Enhancing EBD would be a key strategy7for improving power density in capacitors and other energy storage applications.

[0006] Polymer-ceramic composites could have synergistic effects where polymer retains its processibility and flexibility while the high permittivity ceramic fillers like Barium Titanate (BaTiOs) and Calcium Copper Titanate or CaCu3Ti40i2 (CCTO) improves dielectric properties, forming highly adaptable material for energy storage and capacitor technologies where performance and manufacturability are critical. However, a long-standing issue is the compromise in EBD known in composites due to the formation of conductive pathways along the fillers.BRIEF SUMMARY OF THE INVENTION

[0007] According to embodiments of the present disclosure, the inventors demonstrate a method to create high energy density composite films for applications such as dielectric capacitors. In particular, the inventors demonstrate i) that electrical conduction at high fields can be suppressed by confinement of polymer chains by preparing films below or near its radius of gyration, thereby enhancing EBD, and ii) that dielectric permittivity7can be increased by incorporating ceramic fillers without sacrificing EBD. In combination, such films produce high energy storage capacity (equation above).

[0008] Poly(methyl methacrylate) (PMMA) and polydimethylsiloxane (PDMS) are two polymers of significant interest because they offer unique advantages for dielectric applications. PMMA has apolar chemical structure that enables uniform dispersion of fillers within its structure. On the other hand, PDMS, a widely used dielectric elastomer, serves as an ideal model system for exploring strategies to enhance EBD without compromising other 260273295key properties. Extensively employed in dielectric elastomer actuators (DEAs). PDMS holds great potential in miniaturized electronics and biomedical devices, such as robotics and therapeutic applications. However, the enhancements in dielectric properties described herein relate not only to PMMA and PDMS but are also applicable to polyacrylates, polysty rene (PS), and poly(2-vinyl pyridine), poly(4-vinyl pyridine), and can be extended to (i) thermoplastics, such as polyamides, polyesters, polyolefins, polyimides, polyetherimides, polyaryletherketones, and their copolymers and composites thereof, (ii) thermosets, such as polyepoxy, polycyanurates, phenolic resins, and their copolymers and composites thereof, and (iii) halogenated polymers, such as polyvinylidiene fluoride, polytetrafluoroethylene, poly chlorofluoroethylene, and their copolymers and composites thereof.

[0009] PDMS has in particular been limited in high-voltage applications due to its relatively low dielectric breakdown strength. As will be described more fully below, the dielectric breakdown strength of nanoscale PDMS films (down to 15 nm) w as explored, and the inventors were able to demonstrate improvement to the material's electrical performance while maintaining its advantageous mechanical properties. In this way, safer, more efficient DEAs can be developed, addressing safety concerns related to high electric fields by enhancing the breakdown strength of PDMS through morphological control, particularly by manipulating film thickness and crosslinking density.

[0010] Specifically, reducing film thickness to the nanoscale and adjusting crosslinking density is shown to substantially increase breakdown strength. In thinner films, extended polymer chains have lower free volume and are less likely to form microvoids, which often initiate breakdown, unlike bulk films with coiled chains. Higher crosslinking also improves breakdown resistance by minimizing defects and reducing chain mobility. The inventors expect that this approach will allow for higher breakdown strength in PDMS films used in high-voltage applications while maintaining key properties like polarization and capacitance.

[0011] Previous studies have explored the dielectric breakdown of PDMS films with thicknesses ranging from 2 pm to 14 pm. demonstrating that breakdown strength strongly depends on electrode gap and geometry, with reported values between 250 and 635 V / pm. These findings have provided critical insights into the limits of PDMS thin films used in electromechanical microsystems. The research revealed that PDMS films could achieve 360273295nearly 10* the dielectric strength of air gaps of similar size, highlighting the potential of PDMS as a robust insulating material.

[0012] However, existing work has focused mainly on micron-scale films, leaving a significant gap in the understanding of PDMS behavior at the nanoscale. To date, the inventors are aware of no studies that have comprehensively investigated how film thicknesses below 1 pm affect dielectnc breakdown strength, particularly in the context of DEAs and other high-voltage applications.

[0013] Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0015] FIG. 1 schematically depicts a polymer electronic component having an insulating polymer layer, according to one or more embodiments of the present disclosure;

[0016] FIGS. 2A and 2B depict a plot showing the EBD of PDMS vs film thickness (FIG.2A), EBD of PMMA VS film thickness (FIG. 2B);

[0017] FIG. 2C depicts a dielectric film structure in which a polymer dielectric film is separated from a substrate by polymer brushes;

[0018] FIG. 2D depict a plot showing the EBD VS film thickness for a PMMA film applied directly to a substrate as compared to a PMMA film separated from the substrate by PMMA brushes;60273295

[0019] FIGS. 3A and 3B depict a plot showing the EBD of PDMS vs number of layers (FIG. 3A) and schematic representation of layer blending of successive PDMS layers into continuous, homogeneous films with internal breakdown pathways (FIG. 3B);

[0020] FIGS. 4A-4E depict a plot of measured polarization (pC / cm2) as a function of drive field (kV / cm) for a 100 nm layer of a PMMA-BATiOs nanocomposite on an Si wafer (FIG. 4A), a plot of measured polarization (pC / cm2) as a function of drive field (kV / cm) for a 500 nm layer of a PDMS films on an Si wafer (FIG. 4B), and plots of measured polarization (pC / cm2) as a function of drive field (kV / cm) for stacks of alternating layers (3, 5, and 7 total layers) of PDMS films and PMMA-BATiCh nanocomposite films on an Si wafer (FIGS. 4C-4E);

[0021] FIGS. 5A and 5B depict graphs of the dielectric strength as a function of film thickness for a polymer with a glassy morphology (FIG. 5A) and for a PDMS film (FIG. 5B);

[0022] FIGS. 5C and 5D depict graphs of the breakdown voltage for the glassy films (FIG. 5C) and for an elastomeric film (FIG. 5D);

[0023] FIG. 6A depicts a graph of electric breakdown field for PMMA films on various substrate materials;

[0024] FIGS. 6B and 6C depict graphs of electric breakdown strength for PMMA films (FIG. 6B) and PDMS films (FIG. 6C) spin-coated directly onto the substrate without brushes and with brushes as measured at room temperature, at 100 °C. at 150 °C, and at 200 °C;

[0025] FIGS. 6D and 6E graphically demonstrate the effect of brush length on breakdown field (kV / cm) and breakdown voltage (V) for a PMMA film;

[0026] FIG. 7A schematically illustrates the swelling of ultrathin films compared to bulk films;

[0027] FIG. 7B is a graph showing percent swelling as a function of original film thickness;560273295

[0028] FIG. 7C is a graph of swelling for PDMS films provided direction on a silicon substrate and connected to the silicon substrate with a brush layer;

[0029] FIG. 8 is a plot of interfacial voltage drop (Vint) against contact angle;

[0030] FIG. 9A depicts a charge-discharge hysteresis loop of PMMA thin films at 150 nm thickness, subjected to an electric field of 22,667 kV / cm;

[0031] FIG. 9B depicts energy density and charge-discharge efficiency of PMMA thin films across an electric field in a range of 9000 kV / cm to 24,000 kV / cm;

[0032] FIGS. 10A and 10B show the charge-discharge hysteresis loop and the energy density and efficiency of PDMS thin films (-200 nm thickness) across an electric field in a range of 13,000 kV / cm to 18,500 kV / cm;

[0033] FIGS. 11A and 11B show the charge-discharge hysteresis loop and the energy density and efficiency of a composite film of PMMA and BaTiOs; and

[0034] FIG. 12 is a dielectric fatigue plot of the charge-discharge cycling for PDMS films, according to an embodiment of the present disclosure.

[0035] While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.DETAILED DESCRIPTION OF THE INVENTION

[0036] Embodiments of the present disclosure demonstrate the effects of polymer morphology, specifically film thickness and crosslinking density, on dielectric behavior. According to the present disclosure, increasing the crosslinking density, achieved by adjusting the proportion of the curing agent, is shown to result in a decrease in the dielectric constant (k). However, despite this reduction in the dielectric constant, the inventors surprising and unexpectedly found that modifying the crosslinking density allowed for 660273295desirable mechanical and dielectric properties simultaneously, especially when the thickness of the fdm was reduced below 1 pm. Such enhancements to the electrical and mechanical performance of insulating polymers are expected to expand utilization of insulating polymers in such applications as capacitors and actuators. These and other aspects and advantages will be described more fully in relation to the embodiments provided below and in relation to the figures. These embodiments are presented by way of illustration and not limitation.

[0037] FIG. 1 depicts a polymer electronic component 100 according to an exemplary embodiment of the present disclosure. In one or more embodiments, the polymer electronic component 100 includes a dielectric material 102 disposed between a first electrode 104 and a second electrode 106. As can be seen, a voltage is applied across the first electrode 104 and the second electrode 106 to cause a mechanical response of the dielectric material 102 or to store charge in the dielectric material 102. Examples of polymer electronic components 100 having the disclosed structure include a dielectric elastomer actuator (DEA), electrical insulation, safety coatings, and a polymer capacitor for pulse power, power conditioning, transformer and energy storage capabilities, amongst other possibilities. The miniaturized polymer dielectrics presented have emerging applications in electronic devices like memory devices, field-effect transistors, and triboelectric nanogenerators.

[0038] In one or more embodiments in which the polymer electronic component 100 is a DEA. the dielectric material 102 is an elastomer, and the first electrode 104 and the second electrode 106 are compliant. By "compliant," it is meant that the electrodes 104, 106 are configured to expand and contract with the elastomeric dielectric material 102 when a voltage is applied across the electrodes 104, 106 that causes the elastomeric dielectric material 102 to expand or contract. When the voltage is removed from the electrodes 104, 106, the elastomeric dielectric material 102 will contract or expand (i.e., opposite to when the voltage is applied), and the electrodes 104, 106 will contract or expand with the elastomeric dielectric material 102.

[0039] In one or more embodiments in which the polymer electronic component 100 is a DEA. the dielectric material 102 comprises one or more elastomers selected from polysiloxanes such as poly dimethylsiloxane (PDMS), polymethylhydrogensiloxane (PMHS), polydiethylsiloxane (PDES), fluorinated polysiloxane, or polydiphenylsiloxane (PDPS). In 760273295one or more such embodiments, the compliant electrodes 104. 106 are comprised of aluminum, nickel, gold, silver, copper, gallium and indium.

[0040] In one or more embodiments in which the polymer electronic component is a polymer capacitor, the dielectric material 102 comprises a one or more polymers selected from PMMA, PDMS, polyacrylates, polystyrene (PS), poly(2-vinyl pyridine), poly(4-vinyl pyridine), thermoplastics (such as polyamides, polyesters, polyolefins, polyimides, polyetherimides, poly aryl etherketones, and their copolymers and composites thereof), thermosets (such as polyepoxy, polycyanurates, phenolic resins, and their copolymers and composites thereof), and halogenated polymers (such as polyvinylidiene fluoride, polytetrafluoroethylene, polychlorofluoroethylene, and their copolymers and composites thereof). In one or more such embodiments, the dielectric material 102 is a composite material in that the dielectric material comprises the polymer material and a filler having a high permittivity, in particular a permittivity of at least 500 F / m, more particularly within a range of 500 F / m to 5000 F / m or more depending on particle size and processing conditions. In one or more embodiments, the filler comprises at least one of barium titanate (BaTiCfi), calcium copper titanate (CaCwluOn), strontium titanate (SrTiOs), titanium dioxide (TiCh), lead magnesium niobate-lead titanate (PLZT) and graphene nano particles. In one or more embodiments, the composite polymer dielectric material 102 comprises from 10 wt% to 30 wt% of the high permittivity filler.

[0041] In one or more embodiments in which the polymer electronic component 100 is a polymer capacitor, the dielectric material 102 comprises a stack of alternating layers of the elastomer material and the composite material. For example, in one or more embodiments, the dielectric material 102 comprises a first layer of PDMS, a second layer of PMMA with BaTiO? filler, a third layer of PDMS, a fourth layer of PMMA with BaTiCh filler, a fifth layer of PDMS, etc. In one or more embodiments, the stack comprises a total of up to 20 layers.

[0042] In one or more embodiments in which the polymer electronic component 100 is a polymer capacitor, the electrodes 104, 106 comprise at least one of aluminum, nickel, gold, silver, copper, gallium and indium.860273295

[0043] In one or more embodiments, the polymer electronic component 100 is stacked or rolled to provide a larger component or to increase the charge storage capacity. For example, multiple DEA can be stacked with alternating layers of elastomeric polymer material 102 and electrodes 104, 106 to produce a larger actuator, e.g., for use as robotic muscle. In another example, multiple polymer capacitors can be stacked or rolled to increase the capacitance of the polymer capacitor.

[0044] According to the present disclosure, the dielectric material 102 is provided at a thickness of 1 pm or less. The inventors surprisingly and unexpectedly found that the dielectric breakdown strength of the dielectric material 102 substantially increased at thicknesses below 1 pm, in particular 500 nm and lower, and most particularly in a range of about 15 nm to about 500 nm. In one or more embodiments, the dielectric material 102 comprises a dielectric breakdown strength (EBD) of at least 10,000 KV / cm, in particular at least 100,000 KV / cm, when provided at a thickness of 1 pm or less, in particular in a range of 15 nm to 500 nm.

[0045] In one or more embodiments, films of the dielectric material 102 having the thickness described can be produced in any of a variety of suitable ways, including spin coating, drop casting, dip coating, film blowing, knife casting, electrospray, or electrohydrodynamic printing. In one or more embodiments, the dielectric material 102 may be formed from a solution, such as a multi-part solution, especially where the dielectric material 102 is an elastomer (e.g., PDMS). In one or more such embodiments, the multi-part solution can be prepared by combining the elastomer base with a curing agent, and the degree of crosslinking can be controlled by the adjusting the ratio of elastomer base to curing agent. In one or more embodiments, the density of crosslinking is in a range of 2 xlO20cm'3to 7 xlO20cm’3.

[0046] In one or more other embodiments, the dielectric material 102 may be formed from a solution in which a powdered form of the dielectric material (e.g., PMMA) is dissolved in a solvent, such as acetone, chloroform, hexane, dimethyl formamide, N-methyl-2-pyrrolidone and propylene glycol methyl ether acetate. In one or more such embodiments, the filler material may also be included in the solution containing the powdered form of the dielectric material.960273295

[0047] After the solution is prepared, the solution can be used in any of the foregoing fdm forming methodologies according to techniques known by those of ordinary skill in the art. In one or more embodiments, the fdm formed from the coating solution is cured, and curing may take place at ambient temperature and pressure or at elevated temperature and / or reduced pressure.

[0048] PDMS thin fdms were stable towards thermal annealing up to 150°C, maintaining EBD whereas glassy fdms such as PMMA were stable up to 100°C. In both cases, the addition of a polymer brush layer between the electrode and the polymer fdm with matching chemistry i.e. PDMS on PDMS brush, improved stability of the fdms towards thermal annealing up to 200°C, albeit the addition of brush layers lowers the EBD by a factor of 2 due to relaxation of the interface.

[0049] PDMS, glassy and composite thin fdms with high EBD showed extraordinary recoverable energy densities between 78-133 J / cm3. Moreover, high charge-discharge efficiencies (>90%) are obtained despite application of fields near the dielectric breakdown strength EBD (90% breakdown field).

[0050] In view of the foregoing description, PDMS can be taken as an exemplary dielectric material 102 for discussion. PDMS has widespread applications as a dielectric elastomer actuator (DEA), where performance is strongly influenced by its dielectric constant (k) and the square of the applied electric field (E). In today's rapidly advancing world, the trend toward miniaturizing electronics is increasingly important, as smaller, more efficient components are crucial for modem devices. Thin films, like PDMS, play a vital role in this miniaturization process, offering the potential to maintain high-performance standards while reducing size. Additionally, PDMS-based DEAs show immense promise in fields like robotics and therapeutic devices, including stroke rehabilitation, where they could mimic muscle movements by applying controlled forces, thereby enabling more natural interactions in these applications. However, PDMS use in DEAs is limited by the high electric fields required for operation, which presents significant safety risks. Such concerns are addressed according to the present disclosure by enhancing the dielectric breakdown strength (EBD) of polymers without compromising other key properties.1060273295

[0051] Further, according to the present disclosure, the effect of film thickness on dielectric breakdown strength is demonstrated. For thicker PDMS films (~40 pm), the average Weibull breakdown strength was measured to be 1888 kV / cm. Remarkably, when the film thickness was reduced to 15 nm, a dramatic increase in breakdown strength was observed, reaching an average of 200 MV / cm, an increase of approximately 10,443%. This extraordinary enhancement in breakdown strength is attributed to increased contribution of interfacial resistance at the electrode polymer interface, lateral chain stretching in sub-micron films and proportional decay in the polarizability of the polymer.

[0052] Based on these findings, the inventors surmise that, by manipulating the crosslinking density and film thickness, polymer films can be engineered with enhanced dielectric properties, making them ideal for miniaturized electronics and improving their safety and viability7in high-power density applications. These insights also contribute to the development of robust and efficient DEAs for use in advanced fields such as robotics and therapeutic devices, enabling potential breakthroughs in stroke rehabilitation and similar areas where muscle-mimicking movements through controlled forces are essential.

[0053] EXPERIMENTAL EXAMPLES

[0054] Materials

[0055] PDMS samples were fabricated using a two-part Sylgard 184 silicone elastomer kit, obtained from Ellsworth Adhesives. PMMA was purchased from Polymer Source, while BaTiCL spherical nanopowder (50-70 nm, 99.9% purity) was procured from Sky spring Nanomaterials. All materials were used as received without further modification.

[0056] Fabrication of Polymer Films

[0057] PDMS Films

[0058] Bulk PDMS films were prepared by mixing the Sylgard 184 elastomer base with the curing agent at a crosslinking ratio of 10:1 (w / w). The components were thoroughly mixed, degassed under vacuum to remove trapped air bubbles, and solution-cast onto glass1160273295substrates with thicknesses ranging from 2.5 jam to 40 pm. achieved using a knife coater. The films were cured in an oven at 80 °C for 5 hours to ensure complete crosslinking and curing.

[0059] Thin PDMS films were fabricated using a spin-coating technique. The elastomer base and curing agent were mixed at a 10:1 ratio (w / w), dissolved in hexane, and vortexed thoroughly to ensure uniformity. The resulting solution was spin-coated onto bare N-type P-doped) silicon wafers supplied by MSE Supplies. The films were cured at 80 °C for 3 hours, a shorter curing duration due to the reduced film thickness. By varying the PDMS-hexane solution concentration, spin speeds, and coating durations, thicknesses ranging from 500 nm to 15 nm were achieved. For instance, a 15 nm film was obtained by casting a 0.5% PDMS solution at a spin speed of 2000 rpm for 30 seconds.

[0060] PMMA Films

[0061] PMMA thin films were fabricated using a spin-coating process. PMMA powder was dissolved in acetone and vortexed thoroughly to ensure a homogeneous solution. Film thicknesses were controlled by adjusting the PMMA solution concentration, spin speed, and coating duration, and film thicknesses were measured using ellipsometry. For example, a 14 nm PMMA film was obtained using a 0.5% PMMA solution spun at 2000 rpm for 30 seconds.

[0062] Fabrication of Composite Films and Layered Structures

[0063] PDMS layering was achieved by spin-coating a 15 nm PDMS solution (prepared as described above) onto a silicon wafer and curing it in an oven. Additional PDMS layers were sequentially spin-coated and cured, repeating the process to achieve the desired number of layers in a stack.

[0064] PMMA-BaTiOs (PM: Ba) composite films were prepared by first dispersing BaTiCL nanoparticles into acetone and sonicating for one hour to achieve complete dispersion. PMMA powder was then added to the BaTiOs-acetone mixture and vortexed to ensure complete dissolution and uniformity. A 70:30 (w / w) PMMA-BaTiCh ratio was used, with a final solution concentration of 2%. This ensured the nanoparticles were well-dispersed1260273295within the PMMA matrix. The composite solution was spin-coated onto silicon wafers and allowed to sit at room temperature for several hours to enable complete solvent removal.

[0065] A layered PDMS-PMMA:BaTiO3 (PD-PM:Ba) structure was fabricated by first spin-coating a PDMS layer onto a silicon wafer and curing it at 80°C. A PM:Ba composite layer was then spin-coated onto the cured PDMS layer and allowed to sit at room temperature for solvent evaporation. Another PDMS layer was subsequently spin-coated over the PM:Ba layer, creating a sandwich structure. The resulting stack was cured at 40 °C for 12 hours, as a lower temperature and extended curing time prevent nanoparticle coagulation or segregation within the PM:Ba matrix. This process was repeated until the desired number of layers is achieved in the stack.

[0066] Characterization

[0067] The polarization loops and dielectric breakdown strength of all films were characterized using a Poly-K ferroelectric analyzer system, connected to a Trek high-voltage supply / controller (Model 610C) amplifier. For dielectric breakdown measurements, at least eight samples were tested for each material in which voltage was ramped through the films at a rate of 20 V / s, and the results were analyzed using Weibull statistical analysis to determine the characteristic breakdow n strength. All measurements were conducted in Galden HT-270 insulating fluid, supplied by TMS Industries, to ensure accurate results and prevent premature breakdown due to air exposure.

[0068] Dielectric Breakdown Strength of PDMS Films

[0069] The EBD of PDMS films was evaluated across a range of thicknesses, from 40 pm bulk films dow n to 15 nm thin films. As shown in FIG. 2A, the EBD for bulk films (4 pm to 2.5 pm) remains relatively constant, likely due to minimal differences in thickness, which fail to produce significant variations in EBD. However, the present disclosure demonstrates the dramatic enhancement in EBD observed as film thickness decreases. Bulk PDMS films displayed a characteristic EBD of -1888 kV / cm, while the 15 nm films exhibited a surprising and unexpected increase to -200,000 kV / cm, an enhancement of approximately 10,443% as shown in FIG. 2A.1360273295

[0070] The inventors atribute this remarkable improvement to extended chain conformation and lateral chain stretching in submicron films, alongside a proportional reduction in polarizability and free volume within the polymer matrix. To determine if this behavior is unique to PDMS, similar tests were conducted on PMMA films in the submicron regime. As shown in FIG. 2B, PMMA films displayed an EBD of -374,000 kV / cm, consistent with available literature. This confirms that the observed dielectric enhancement is not exclusive to PDMS but may be a general phenomenon across polymers, regardless of their polarity.

[0071] FIG. 2C depicts a dielectric film structure 200 having a substrate 210 on which a polymer dielectric film 220 is disposed. The polymer dielectric film 220 is separated from the substrate 210 by a plurality of polymer brushes 230. The brushes 230 reduce interfacial effects caused by the combination of the substrate 210 and the polymer dielectric film 220. In this way, the effects of the thickness of the polymer dielectric film 220 can be isolated from the substrate 210. As shown in the graph of FIG. 2D, the dielectric film structure 200 having the polymer dielectric film 220 of PMMA separated from the substrate 210 by brushes 230 of PMMA performs substantially the same as the polymer dielectric film 220 of PMMA applied directly to the substrate 210.

[0072] Building upon the surprising and unexpected EBD observed in thin films, atempts were made to scale up the thickness of PDMS films by creating multilayered structures. PDMS films of 15 nm thickness were sequentially spin-coated and cured to form stacks of 1, 4, 12, and 18 layers. However, as show n in FIG. 3 A, the EBD of these multilayered structures decreased significantly with increasing layers, converging to values similar to bulk films of equivalent total thickness. As shown in FIG. 3B, this decline is atributed to the blending of successive PDMS layers 300, which form continuous, homogeneous films with internal breakdown pathways 310.

[0073] To overcome the blending issue and enhance the dielectric performance, a strategy was devised to introduce a separating layer of a different polymer with high &. PMMA-BaTiOs (PM:Ba) nanocomposites were chosen for this purpose, as BaTiO? is known for its high Sr. Inorganic layers such as oxides and metals can be deposited as the separating layers1460273295for example using chemical vapor deposition, atomic layer deposition, and aerosol spray coating.

[0074] The PM:Ba fdms were fabricated by creating a solution as described above and spin-coating the solution into 100 nm films. FIG. 4A depicts a dielectric film structure 200 including a substrate 210 and a nanocomposite film 400. As shown in the graph of FIG. 4A, the dielectric film structure 200 comprising the nanocomposite film 400 exhibited excellent dielectric properties with an energy density of 1.3 J / cm3and an efficiency of 82.4%. In comparison, FIG. 4B depicts a dielectric film structure 200' including a substrate 210' with a pristine PDMS film 220' having a thickness of 500 nm. As shown in the graph of FIG. 4B, the dielectric film structure 200' displayed negligible polarization and much lower energy density (-0.003 J / cm3) and efficiency (77.1%) (FIG. 4B) consistent with conventional PDMS dielectrics, emphasizing the superior dielectric behavior of the ultrathin PM:Ba nanocomposite films 400.

[0075] To integrate the high EBD of PDMS with the high polarization of PM:Ba, layered PDMS-PM:Ba sandwich structures 500 were fabncated as shown in FIGS. 4C-4E. In the sandwich structures 500, a 70 nm PDMS layer 220 was spin-coated and cured, followed by a 100 nm PM:Ba nanocomposite layer 400, and capped with another PDMS layer 220 (FIG.4C), referred to as "2-l / PD-PM:Ba." This structure was repeated to create stacks with three PDMS layers 220 and two PM:Ba nanocomposite layers 400 (FIG. 4D), referred to as "3-2 / PD-PM:Ba," and four PDMS layers 220 and three PM:Ba nanocomposite layers 400 (FIG.4E), referred to as 4-3 / PD-PM:Ba."

[0076] As shown in the graphs of FIGS. 4C-4E, while the initial PD-PM:Ba stacks displayed lower performance than single PM:Ba films, the overall energy density increased with additional layers, reaching 0.22 J / cm3and an efficiency of 81% for the 4-3 / PD-PM:Ba structure. This improvement is likely due to the cumulative effect of multiple PM:Ba layers, which enhance polarization and contribute to the overall dielectric strength. Although the EBD of the PM: Ba film w as reduced compared to pristine PMMA films, the introduction of BaTiOs fillers into the confined PMMA matrix achieved a significant enhancement in dielectric properties without severely compromising the breakdow n strength.1560273295

[0077] With reference to FIGS. 5A-5D, polymer morphology was investigated. As shown in FIG. 5 A, the dielectric strength increases above bulk values for polymers having a glassy morphology when the film thickness drops below approximately 1 pm, with a sharp rise in strength for films thinner than 400 nm. For example, PMMA films at 14 nm exhibited a breakdown strength of 206.402 kV / cm, nearly 20 times higher than at 1 pm. Similarly. PS films at 25 nm and P4VP films at 22 nm showed breakdown fields of 57,892 kV / cm and 190,096 kV / cm, respectively.

[0078] FIG. 5B shows that, for elastomeric PDMS films, the dielectric strength initially decreased with thickness but sharply increased below 500 nm, indicating that the enhanced breakdown strength phenomenon applies to both glassy and elastomeric polymers. This highlights the potential for designing high-energy-density capacitors for advanced applications.

[0079] FIGS. 5C and 5D present the breakdown voltage data for the glassy and elastomeric films. While the breakdown voltage decreases gradually with decreasing thickness, the enhanced breakdown strength cannot be attributed to thickness alone, suggesting the involvement of additional material factors.

[0080] With reference to FIGS. 6A-6E, the effect of substrate type on the dielectric breakdown strength (EBD) of PMMA films was investigated by spin-coating the PMMA films onto different substrates: silicon wafer, gold, nickel, and aluminum. As shown in FIG. 6 A, the substrate type had no significant impact on EBD, suggesting that, within the materials tested, the substrate does not influence the breakdow n strength of ultrathin polymer films.

[0081] To explore interfacial effects, PMMA brushes were grafted onto a silicon wafer to isolate the polymer from direct substrate interaction. PMMA films (100 nm thick) were spin-coated onto these brush-coated substrates and annealed at temperatures of 100 °C, 150 °C, and 200 °C for 24 hours. As shown in FIG. 6B, for PMMA films spin-coated directly onto the substrate without brushes, the EBD remained stable at room temperature (film 1) and at 100 °C (film 2) but decreased by 71% at 200 °C (film 4), indicating relaxation of the polymer chains and or dewetting of the film at higher temperatures. In contrast, PMMA films on brush-coated substrates (films 5-8) showed a consistent EBD across all annealing 1660273295temperatures indicating that relaxation of the polymer plays a minor role. However, the PMMA films on brush-coated substrates showed a 34% decrease as compared to the room temperature PMMA film directly on the substrate (film 1). This suggests a significant role of surface interactions as the brush layer severs the contact between the polymer and substrate electrode.

[0082] This procedure was replicated with PDMS films and PDMS brushes as shown in FIG. 6C, observing similar behavior. However, the EBD of the PDMS film showed more thermal stability' due to cross-linking in which significant reduction (-1500 kV / cm) was only observed at 200 °C (film 4) as compared to room temperature (film 1). By contrast, the EBD of the PDMS films on brush-coated substrates remained relatively stable across the temperature range of room temperature to 200 °C. While the EBD is lower overall than for any of the PDMS films applied directly to the substrate, the stability of EBD over a range of temperatures may be a more valuable property in certain applications.

[0083] The results depicted graphically in FIGS. 6B and 6C suggest that the observed effects are attributable to interfacial interactions rather than the molecular weight or glass transition temperature (Tg) of the polymers. For PDMS, which has a negative glass transition temperature (Tg) and was annealed above its glass transition temperature (Tg), the stability7can be attributed to the interface control rather than material properties.

[0084] FIGS. 6D and 6E graphically demonstrate the effect of brush length on breakdown field (kV / cm) and breakdown voltage (V) for a PMMA film. As can be seen, the increasing brush length causes a decrease in both breakdown field (from about 215,000 kV / cm to about 115,000 kV / cm) and breakdown voltage (from about 75 V to about 63 V).

[0085] To validate the impact of conformational and interfacial effects on the EBD, a swelling test was conducted on PDMS films of varying thicknesses using a solvent annealing chamber. Films were exposed to hexane vapor at a fixed activity, and the swelling behavior of the films was observed. FIG. 7A schematically illustrates the swelling of ultrathin films compared to bulk films. As can be seen in FIG. 7A, bulk films swell to a greater degree than thin films in that the percent increase in film size relative to the initial film size is greater.1760273295

[0086] This observation is confirmed in FIG. 7B, which shows the percent swelling as a function of original film thickness. In particular, the 20 nm thin film swelled by 25%, whereas the 2.5 pm bulk film swelled by 55%. This result indicates that thinner films are more resistant to swelling, suggesting that ultrathin films are either tightly bound to the surface or exist in a non-equilibrium conformation in which polymer chains are stretched, both of which limits their ability to swell and explains the improvement in EBD.

[0087] Additionally, PDMS films were tested on different substrates, including PDMS brush-coated and plain silicon substrates as shown in FIG. 7C. The PDMS-brush films swelled 5% more than the plain films. This confirms chain relaxation at the interface, which allows for more solvent absorption, but the limited difference indicates that the interfacial effects are more dominant. This relaxation led to a decrease in EBD, further emphasizing the role of interfacial effects in determining the dielectric properties.

[0088] The breakdown voltage of ultrathin PMMA, PDMS, PVP, and PS films were extrapolated to obtain an interfacial breakdown voltage, V int. This represents contribution of the polymer-electrode interface to EBD. The V_int correlates well to the contact angle of the polymers (FIG 8), confirming that polymers which form favorable interface with the electrode results in higher EBD.

[0089] Capacitor Performance

[0090] FIG. 9A shows the charge-discharge hysteresis loop of PMMA thin films at 150 nm thickness, subjected to an electric field of 22,667 kV / cm. The film demonstrates low-loss behavior wdth 75% efficiency before breakdown and a recoverable energy density of 85.2 J / cm3, which is the highest reported for any polymer capacitor film. These performance achievements highlight the potential of fabrication techniques to enhance EBD and revolutionize energy storage.

[0091] FIG. 9B presents energy density and charge-discharge efficiency at different fields. Energy density increases wdth the field, while efficiency remains relatively high up to 75% before approaching the breakdow n field, suggesting that these films can store energy1860273295efficiently across varying conditions. The results emphasize the high performance and stability' of these films, underscoring their potential for use in high-performance capacitors.

[0092] FIGS. 10A and 10B show the charge-discharge hysteresis loop and the energy density and efficiency of PDMS thin films (-200 nm thickness) at an electric field of 18,500 kV / cm. The film demonstrates low-loss behavior with over 90% efficiency before breakdown and a recoverable energy density of 78 J / cm3, which is the largest reported for silicone elastomers. FIG. 10B shows that energy density increases with the electric field, while efficiency stays high at 91% before approaching breakdown, indicating the films' ability to store energy efficiently under varying conditions.

[0093] Similarly, a composite film of PMMA and BaTiOs was tested. FIGS. 11A and 1 IB present similar results, with a recoverable energy density of 133.4 J / cm3and over 80% efficiency before breakdown. As shown in FIG. 11B, the energy' density7increases with the field, while efficiency remains high and stable up to breakdown, further highlighting the energy storage potential of these films.

[0094] Fatigue testing by sequential charge-discharge cycles as shown in FIG. 12 indicates no degradation in performance where the exceptionally high energy7density and efficiency remained stable after at least 1,000,000 cycles.

[0095] All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0096] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range,1960273295unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e g., ‘‘such as?’) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0097] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.2060273295

Claims

1. WHAT IS CLAIMED IS:

1. A dielectric film, comprising:an elastomeric or composite insulating polymer having a thickness of 1 pm or less; anda dielectric breakdown strength of at least 10,000 kV / cm.

2. The dielectric film of claim 1, wherein the elastomeric or composite insulating polymer comprises a polysiloxane.

3. The dielectric film of claim 2, wherein the poly siloxane comprises at least one of poly dimethylsiloxane (PDMS), polymethylhydrogensiloxane (PMHS), poly diethylsiloxane (PDES), fluorinated polysiloxane, or poly diphenylsiloxane (PDPS).

4. The dielectric film of claim 1, wherein the elastomeric or composite insulating polymer comprises at least one of poly(methyl methacrylate) (PMMA). polyvinylidene fluoride (PVDF), a poly(vinylpyridine) (PVP), polystyrene (PS), a polyacrylate, polystyrene (PS), a thermoplastic selected from a group consisting of a polyamide, a polyester, a polyolefin, a polyimide, a polyetherimide, a polyaryletherketone, and a copolymer or a composite thereof, a thermoset selected from a group consisting of a polyepoxy, a polycyanurate, a phenolic resin, and a copolymer or composite thereof, or a halogenated polymer selected from a group consisting of a polyvinylidiene fluoride, a polytetrafluoroethy lene, a poly chlorofluoroethylene, and a copoly mer or composite thereof.

5. The dielectric film of claim 4, wherein the elastomeric or composite insulating polymer further comprises a filler dispersed within the insulating polymer, the filler comprising a permittivity of at least 500 F / m.21602732956. The dielectric film of claim 5, wherein the filler comprises at least one of barium titanate (BaTiCh), calcium copper titanate (CaCu3Ti40i2), strontium titanate (SrTiCh), titanium dioxide (TiCh), lead magnesium niobate-lead titanate (PLZT), or graphene nano particles.

7. The dielectric film of claim 5 or claim 6, comprising from 10 wt% to 30 wt% of the filler.

8. The dielectric film of any of claims 5-7, wherein the dielectric film comprises a stack of alternating layers of (i) an elastomeric material and (ii) a composite material comprising the filler.

9. A polymer electronic component, comprising:a first electrode;a second electrode; andthe dielectric film according to any of claims 1-8, the dielectric film being disposed between the first electrode and the second electrode.

10. The polymer electronic component of claim 9, wherein the polymer electronic component is a dielectric elastomer actuator.

11. The polymer electronic component of claim 10, wherein the polymer electronic component is a capacitor.

12. The polymer electronic component of claim 11, wherein the capacitor comprises a recoverable energy density at least 75 J / cm3.226027329513. The polymer electronic component of claim 11 or claim 12, wherein the capacitor comprises a charge-discharge efficiency of >90% throughout and at least 75% in an electric field up to the dielectric breakdown strength.

14. A method of preparing a dielectric film, comprising:preparing the dielectric film from an elastomeric or composite insulating polymer; wherein the dielectric film has a thickness of 1 pm or less and a dielectric breakdow n strength of at least 10,000 kV / cm.

15. The method of claim 14, wherein preparing further comprises spin coating, drop casting, dip coating, film blowing, knife casting, electrospray, or electrohydrodynamic printing.

16. The method of claim 14 or claim 15, wherein the dielectric film is prepared from a multi-part solution comprising an elastomeric or composite insulating polymer base and a curing agent.

17. The method of any of claims 14-16, wherein the elastomeric or composite insulating polymer comprises a polysiloxane.

18. The method of claim 17, wherein the polysiloxane comprises at least one of poly dimethylsiloxane (PDMS), polymethylhydrogensiloxane (PMHS), poly diethylsiloxane (PDES), fluorinated polysiloxane, or poly diphenylsiloxane (PDPS).

19. The method of claim 14 or claim 15, wherein the elastomeric or composite insulating polymer is prepared from a solution comprising a powdered form of the insulating polymer and a solvent.236027329520. The method of claim 19, wherein the elastomeric or composite insulating polymer comprises at least one of poly(methyl methacrylate) (PMMA), polyvinylidene fluoride (PVDF), a poly(vinylpyridine) (PVP), polystyrene (PS), a polyacry late, polystyrene (PS), a thermoplastic selected from a group consisting of a polyamide, a polyester, a polyolefin, a polyimide, a poly etherimide, a polyaryletherketone, and a copolymer or a composite thereof, a thermoset selected from a group consisting of a polyepoxy, a polycyanurate, a phenolic resin, and a copolymer or composite thereof, or a halogenated polymer selected from a group consisting of a poly vinylidiene fluoride, a polytetrafluoroethylene, a poly chlorofluoroethylene, and a copolymer or composite thereof.

21. The method of claim 19 or claim 20, wherein the solution further comprises a filler having a permittivity of at least 500 F / m.

22. The method of claim 21, wherein the filler comprises at least one of barium titanate (BaTiOs), calcium copper titanate (CaCu3Ti40i2), strontium titanate (SrTiOs), titanium dioxide (TiCh). lead magnesium niobate-lead titanate (PLZT). or graphene nano particles.

23. The method of claim 14, wherein the elastomeric or composite insulating polymer comprises a first elastic polymer and a second composite polymer, wherein the preparing the dielectric film further comprises preparing alternating layers of the first elastomeric polymer and the second composite polymer, and wherein the composite polymer comprises a filler.

24. The method of claim 14, wherein the dielectric film comprises of alternating layers between elastomeric or composite insulating polymer and an inorganic or hybrid organic-inorganic layers.

25. A film, comprising:2460273295a layer comprising an elastomeric or composite insulating polymer alternating with layers of inorganic or organic-inorganic hybrid having a thickness of 1 pm or less and a dielectric breakdown strength of at least 10,000 kV / cm; anda substrate.

26. The fdm of claim 25, wherein the substrate is a metal or a semiconductor.

27. The film of claim 25 or claim 26. wherein the substrate comprises silicon wafer, gold, nickel, or aluminum.

28. The film of any of claims 25-27, wherein the layer is isolated from the substrate by a plurality of polymer brushes extending between the layer and the substrate.

29. A film, comprising of a plurality of polymer brushes having a thickness of 10 nm or less and a dielectric breakdown strength of at least 110,000 kV / cm; and a substrate.

30. The method of claim 29, wherein the dielectric breakdown strength remains stable up to 200°C.60273295

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