Piezoelectric Device With Composite Electrode Particles
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Solution Overview
Problem
There is a need for improved piezoelectric materials and methods to enhance the piezoelectric coefficients, particularly the d33 charge coefficient, to improve the performance of piezoelectric devices without relying on lead-based materials like PZT, which pose environmental and health concerns, and to stabilize the piezoelectric response in devices.
Innovation Solution
A piezoelectric device comprising a substrate with a dry piezoelectric layer and contiguously arranged electrically-conductive layers containing particles with different Young's modulus, distributed uniformly to affect stress distribution and enhance the piezoelectric charge coefficient d33, along with signal processing electronics and optional proof mass, forming a composite article structure that improves the piezoelectric response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lead-based piezoelectric materials like PZT are used to achieve high piezoelectric coefficients, then the piezoelectric performance is improved, but environmental and public health concerns arise due to lead presence
Solution Approach 1:
The invention changes the chemical composition parameters of piezoelectric materials by incorporating zinc oxide (ZnO) and barium titanate (BaTiO3) particles into polymer matrices, replacing lead-based PZT materials while maintaining or enhancing piezoelectric coefficients through controlled particle size, concentration, and distribution parameters
Solution Approach 2:
The invention creates composite piezoelectric materials by combining polymer matrices with ceramic particles (ZnO and/or BaTiO3), forming a composite structure that achieves high piezoelectric coefficients without using harmful lead-based materials, thus resolving the contradiction between performance and environmental safety
2Reliability
If loose powder is applied on the surface of piezoelectric material to change stress fields, then the piezoelectric charge constant d33 may change, but the transducer becomes mechanically unstable and impractical
Solution Approach 1:
The invention embeds ceramic particles (ZnO and/or BaTiO3) within the polymer matrix, creating a nested structure where particles are contained within the continuous polymer phase, ensuring mechanical stability while maintaining the ability to modify stress fields and enhance piezoelectric coefficients
Solution Approach 2:
The invention incorporates particles into the polymer matrix during the manufacturing process before the final device assembly, ensuring uniform distribution and strong bonding between particles and matrix, which prevents particle dislodging and maintains mechanical stability throughout the device lifecycle
3Reliability
If thick or thin film piezoelectric devices are manufactured to achieve high sensitivity, then device sensitivity is improved, but manufacturing difficulty increases significantly
Solution Approach 1:
The invention uses flexible polymer matrices containing ceramic particles to create thin film piezoelectric devices that can be manufactured using low-cost techniques such as casting, coating, or extrusion, achieving high sensitivity without the complex and expensive manufacturing processes required for traditional thin film piezoelectric devices
Solution Approach 2:
The invention changes the material parameters by using particle-reinforced polymers with tailored particle size, shape, and concentration to achieve desired piezoelectric properties in thin film form factors, enabling high sensitivity devices to be manufactured with simplified processes compared to conventional thick or thin film piezoelectric devices
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively enhances the d33 piezoelectric charge coefficient, improving the performance of piezoelectric devices such as energy harvesters and sensors by directly manipulating the piezoelectric charge coefficient without altering the device structure, providing a stable and efficient piezoelectric response.
Implementation Method 1
Piezoelectric materials are materials that can generate charge and provide voltage when placed under mechanical stress ('piezoelectric effect')
Implementation Method 2
conversely can be deformed under an applied electrical field (the 'converse piezoelectric effect')
Data Source
AI summary
An inertial piezoelectric device has: A) piezoelectric capacitor having a substrate; 2) a dry piezoelectric layer comprising a piezoelectric material; 3) a first electrode arranged contiguously with one opposing surface of the dry PL; and 4) a second electrode arranged contiguously with a second opposing surface of the first dry PL. The first dry electrically-conductive layer consists essentially of: (a) an electrically-conductive material; and (b) particles having a Young's modulus that is different from the Young's modulus of the (a) electrically-conductive material by at least 10%. The device also has B) signal processing electronics in electrical communication with the piezoelectric capacitor; C) a means for converting all or a portion of an applied force to an inertial force that is transmitted to the first dry PL; and optionally D) a proof mass that is contiguous with at least one external surface of the piezoelectric capacitor.