Continuous polarization method for organic piezoelectric film

Abstract

The invention discloses a continuous polarization method for an organic piezoelectric film, and belongs to the field of piezoelectric materials. Due to the fact that a metal wire-shaped corona electrode is arranged in the width direction of the organic piezoelectric film, a uniform polarization electric field can be generated in the width direction of the organic piezoelectric film, and thus uniform polarization of the organic piezoelectric film is achieved. The upper surface and the lower surface of the organic piezoelectric film are not provided with pre-evaporated or coated electrodes, oncea certain point is broken down, intermittent discharge is formed between the corona electrode and a zero electrode, but the polarization voltage can still be maintained; and when the part is driven by a traction device to completely pass through the corona electrode, the intermittent discharge disappears, so that the occasionally generated polarization breakdown point does not influence the implementation of the polarization process. The polarization method provided by the invention can be used for polarization at room temperature and can also be used for polarization at a relatively high temperature, and the polarization temperature range is room temperature to 100 DEG C. In addition, the method has the advantages of simple operation, high working efficiency and the like.

Description

technical field [0001] The invention belongs to the field of piezoelectric materials, in particular to a method for continuous polarization of organic piezoelectric thin films. Background technique [0002] Organic piezoelectric films, especially polyvinylidene fluoride piezoelectric films, have the characteristics of good toughness, impact resistance, high frequency response, and low acoustic impedance. The field has broad application value. [0003] The preparation process of polyvinylidene fluoride piezoelectric film mainly includes: melt extrusion sheet, unidirectional or biaxial stretching crystal transformation, high voltage direct current polarization. Polarization is the basic process for endowing organic piezoelectric films with piezoelectric properties, including contact polarization and non-contact corona polarization. [0004] Contact polarization is a polarization method adopted in the early stage. There are a large number of literature reports, that is, the o...

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Problems solved by technology

[0004] Contact polarization is a polarization method adopted in the early stage. There are a large number of literature reports, that is, the organic piezoelectric film is sandwiched between two metal planes, and a voltage is applied to the upper and lower metal electrodes. Polarization treatment, this method has the following disadvantages: (1) It takes a long time to complete, (2) Generally, it needs to be polarized at a higher temperature (3) Once the organic film has defects and is broken down, the polarization voltage will decrease reduced to zero, the polarization process cannot be completed, (4) it is difficult to achieve continuous polarization

This method can realize the continuous polarization of the organic piezoelectric thin film, but it has the following disadvantages: (1) Each needle-shaped electrode produces a corona ring that radiates outward with the needle as the center, and all the needle-shaped electrodes are in the organic piezoelectric film. Many side-by-side corona rings are generated on the surface of the film, which will inevitably lead to uneven electric field distribution on the organic piezoelectric film, resulting in uneven piezoelectric properties of the organic piezoelectric film; (2) The structure of the needle array electrode is complex and difficult to process

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