Flexible piezoelectric sensor and preparation method thereof

Abstract

The invention relates to a flexible piezoelectric sensor and a preparation method thereof. The flexible piezoelectric sensor is provided with a flexible substrate, a first electrode is arranged on the upper surface of the flexible substrate, a piezoelectric film layer is arranged on the upper surface of the first electrode, a second electrode is arranged on the upper surface of the piezoelectric film layer, and a protective layer is arranged on the upper surface of the second electrode; and the signal transmission sections of the first electrode and the second electrode are separately arranged in a staggered manner. According to the preparation method of the piezoelectric film layer, the mixed solvent with the high boiling point and the low boiling point is adopted for solution preparation, deformation caused by uneven tape casting of the edge part of the film in the forming process is avoided, and meanwhile machining difficulty caused by the fact that the solvent with the low boiling point is prone to volatilization is also avoided; and the piezoelectric sensor prepared by the invention has the advantages of simple structure, small volume, high sensitivity, good flexibility, high piezoelectric constant and good biocompatibility, is suitable for irregular object surfaces, and can be produced on a large scale.

Description

technical field [0001] The invention relates to the technical field of piezoelectric sensors, in particular to a flexible piezoelectric sensor and a preparation method thereof. Background technique [0002] As a sensing element, piezoelectric sensors have been used in a wide range of applications. Typical applications include medical, aerospace, consumer electronics, and nuclear instruments. The traditional and most commonly used piezoelectric sensors mainly use piezoelectric ceramics as piezoelectric materials. Although this sensor has a long history and mature technology, piezoelectric ceramics have shortcomings such as high brittleness, high density, and poor flexibility, which cannot meet complex and diverse applications. The environment, especially in the fields of medical health, robotics, biomechanics, and smart wear, has higher requirements for the flexibility, lightness, and biocompatibility of piezoelectric materials. [0003] Copolymer polyvinylidene fluoride-tri...

AI Technical Summary

Problems solved by technology

The traditional and most commonly used piezoelectric sensors mainly use piezoelectric ceramics as piezoelectric materials. Although this sensor has a long history and mature technology, piezoelectric ceramics have shortcomings such as high brittleness, high density, and poor flexibility, which cannot meet complex and diverse applications. The environment, especially in the fields of medical health, robotics, biomechanics, and smart wear, has higher requirements for the flexibility, thinness, and biocompatibility of piezoelectric materials.

[0003] Copolymer polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) piezoelectric material, as a new type of polymer piezoelectric functional material, has good flexibility, high mechanical strength, easy matching of acoustic impedance, wide frequency response range, and chemical resistance. And oily corrosion, can be processed into a large area and complex shape, etc., has been widely studied, it contains a high piezoelectric phase β phase, the film preparation process does not need to be uniaxially stretched, but the film prepared by the current process The density is not high, and there are many defects. During the polarization process, it is easy to cause high voltage breakdown and uneven polarization, resulting in low piezoelectric constant.

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