An electret includes an electret layer. The electret layer is formed by subjecting a composite film in which inorganic dielectric particles are dispersed and held in a base film to a polarization treatment. The inorganic dielectric particles are mainly composed of an inorganic dielectric material having a bandgap energy of 4 eV or more.

A method for manufacturing a vibration power generation device includes: first silicon substrate patterning for patterning a first silicon substrate to form a first support portion and a fixed electrode finger; second silicon substrate patterning for patterning a second silicon layer of a second silicon substrate in which a first silicon layer and the second silicon layer are laminated to form a movable electrode finger and patterning the first silicon layer to form a second support portion and a movable portion; electret film forming for forming an electret film at one of the movable electrode finger and the fixed electrode finger; and bonding for bonding the first silicon substrate to the second silicon layer side of the second silicon substrate such that the movable electrode finger and the fixed electrode finger face each other.

A flexoelectric structure that includes a flexible ceramic electret portion containing a ceramic component, the flexible ceramic electret portion including a charge retaining ceramic portion and an internal electrode positioned at an internal location of the charge retaining ceramic portion; and a flexible member outside the flexible ceramic electret portion.

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.

The present disclosure describes a strained dielectric material comprising at least one type of component containing a domain wall variant pattern, or superdomain structure, that is in phase-co-existence with, or in close phase proximity to, a paraelectric state achieved at zero electric field or over a finite range of non-zero electric field, wherein the at least one type of component comprises one or more of an in-plane sub-domain polarization component, a plane-normal sub-domain polarization component, or a solid solution of a ferroelectric.

An electret is made by subjecting a composite oxide containing two or more metal elements to a polarization treatment. The composite oxide is a crystalline or non-crystalline oxide containing two different trivalent metal elements A and B, and has a basic composition represented by composition formula A.sub.3B.sub.5O.sub.12. The composite oxide has a band gap energy of 3 eV or more. The metal element A includes at least one element selected from trivalent rare earth elements, and the metal element B includes at least one element selected from trivalent typical elements.

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.