Piezoelectric Element Manufacturing via Phase Transition Control
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Solution Overview
Problem
Existing piezoelectric materials, such as lead zirconate titanate (PZT), have a low electromechanical coupling coefficient, which is insufficient for applications like ultrasonic probes that require efficient energy conversion over a practical temperature range.
Innovation Solution
A method of manufacturing a piezoelectric element with a perovskite-type metal oxide composition, specifically Ba(Ti1-xZrx)O3, where 0.02≤x≤0.13, and incorporating Mn as a sub-component, which involves raising the temperature of the piezoelectric material within a specific range and applying an electric field to enhance the phase transition and piezoelectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If lead-free piezoelectric materials like barium titanate are used to reduce environmental impact, then environmental compatibility improves, but the electromechanical coupling coefficient becomes insufficient for practical applications
Solution Approach 1:
The patent applies parameter changes by precisely controlling the Zr substitution ratio (x) in the range of 0.02≤x≤0.13 and applying electric fields at specific temperature ranges (higher than T(B→A) and lower than T(A→B)) to optimize the piezoelectric properties of lead-free materials, achieving sufficient electromechanical coupling coefficient while maintaining environmental compatibility
Solution Approach 2:
The patent creates a composite material system by substituting Zr for B sites in barium titanate and adding Mn as a sub-component, forming a composite structure Ba(Ti1-xZrx)O3 that combines the advantages of different elements to achieve both environmental friendliness and high electromechanical coupling coefficient
2Reliability
If the electromechanical coupling coefficient is increased for better energy conversion efficiency, then device performance improves, but the manufacturing process complexity increases due to precise temperature and composition control requirements
Solution Approach 1:
The patent defines specific parameter ranges (Zr substitution ratio 0.02≤x≤0.13, temperature between T(B→A) and T(A→B)) that simplify the manufacturing process by providing clear guidance for achieving high electromechanical coupling coefficient without requiring excessive process complexity
Solution Approach 2:
The patent performs preliminary composition design by pre-determining the optimal Zr substitution ratio and Mn content before manufacturing, which simplifies the subsequent production process and reduces manufacturing complexity while ensuring high device performance
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 method achieves a significantly larger electromechanical coupling coefficient in the practical temperature range of 0 to 60°C, improving the efficiency of energy conversion and the reliability of piezoelectric elements for electronic devices.
Implementation Method 1
the piezoelectric material having a low-temperature side ferroelectric phase A and a high-temperature side ferroelectric phase B between which a phase of the piezoelectric material transitions according to a temperature change
Implementation Method 2
starting application of an electric field to the piezoelectric material in a state where the piezoelectric material is held within the temperature range
Data Source
AI summary
A piezoelectric material having a large electromechanical coupling coefficient is provided. The material is manufactured by a method including the steps of: heating a piezoelectric material having a low-temperature side ferroelectric phase A and a high-temperature side ferroelectric phase B between which the phase of the piezoelectric material transitions according to a temperature change, from room temperature to a temperature range higher than T(B→A) at which temperature a change from the ferroelectric phase B to the ferroelectric phase A occurs in a temperature lowering process and lower than T(A→B) at which temperature a change from the ferroelectric phase A to the ferroelectric phase B occurs in a temperature rising process; starting application of an electric field to the piezoelectric material in a state where it is held within this temperature range; and continuing and finishing the electric field application at a temperature lower than T(A→B).