The present disclosure provides a non-linear capacitor comprising a first electrode, a second electrode, and a dielectric layer disposed between said first and second electrodes. The dielectric layer comprises at least one organic compound selected from copolymer, homo-polymer, Sharp polymers, NLSD compounds and combination thereof which have at least one electro-polarizable aromatic polycyclic conjugated core. A relationship between a capacity C of the capacitor and a voltage V between the electrodes is characterized by the monotonously increasing polynomial dependence C.sub.0+.sub.i=1.sup.m C.sub.iV.sup.i, when the voltage V satisfies by following inequality 0<VV.sub.max, where the voltage V.sub.max is a maximum working voltage that does not exceed a breakdown voltage V.sub.bd and which is selected out of safety reasons, where at least one coefficient C.sub.i is not equal to 0 when the index i ranges from 2 to m, and m=2, 3, 4, 5, or 6.

Filter media, such as electret-containing filtration media for filtering gas streams (e.g., air), are described herein. In some embodiments, the filter media may be designed to have desirable properties such as stable filtration efficiency over the lifetime of the filter media, increased normalized gamma, relatively low pressure drop (i.e. resistance), and/or relatively low basis weight. In certain embodiments, the filter media may be a composite of two or more types of fiber layers where each layer may be designed to enhance its function without substantially negatively impacting the performance of another layer of the media. For example, one layer of the media may be designed to have a relatively low basis weight and/or a relatively high air permeability, and another layer of the media may be designed to have stable filtration efficiency and/or a relatively high efficiency throughout the filter media's lifetime. The filter media described herein may be particularly well-suited for applications that involve filtering gas streams (e.g., face masks, cabin air filtration, vacuum filtration, room filtration, furnace filtration, respirator equipment, residential or industrial HVAC filtration, high-efficiency particulate arrestance (HEPA) filters, ultra-low particular air (ULPA) filters, medical equipment), though the media may also be used in other applications.

A variable capacitor device and a method of preparation thereof, wherein the variable capacitor device comprises a shape-memory polymer in its dielectric layer, wherein the shape-memory polymer determines the thickness of the dielectric layer, thereby causing the capacitance of the variable capacitor device to be tuned. Various embodiments of the variable capacitor device and the method of preparing said capacitor have also been provided.

A soft sensor which may be used in robotic grasping applications includes a composite material being reversibly deformable and comprising an elastomer material containing dispersed conductive filler material, wherein the quantity of filler material in the elastomer material is configured to provide a negative change in permittivity of the composite layer upon the composite layer being subjected to a force.

An electret includes a substrate, and an electret layer formed on a surface of the substrate. The electret layer is an inorganic dielectric layer that has been electrically charged. The inorganic dielectric layer includes an outer layer and an inner layer that are stacked in a thickness direction of the substrate. The outer layer contains a first inorganic dielectric material as a main component which is a composite metal compound including different metal elements and has a bandgap energy of 3 eV or more. At least one of the different metal elements being a trivalent metal element. The inner layer contains a second inorganic dielectric material as a main component which is different from the first inorganic dielectric material.

Described herein are electrets and electrical components comprising electrets. Electrical components comprising electrets described herein may be incorporated into power substrates, power electronic modules, and laminated busbars.