Lead-Free Piezoelectric Composition for High Performance
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Solution Overview
Problem
Pb(Zr,Ti)O3 (PZT)-based piezoelectric materials, commonly used due to high piezoelectric characteristics, pose environmental pollution risks due to lead toxicity during the sintering process, necessitating the development of Pb-free alternatives with similar performance.
Innovation Solution
A Pb-free piezoelectric material composition represented by 0.96(NaaK1-a)(Nbb(T1-b))O3-(0.04-x)MZrO3-x(BicAg1-c)ZrO3+d mol % NaNbO3, where T is Sb or Ta, M is Sr, Ba, or Ca, with a specific range for parameters a, b, c, and d, is developed, along with a manufacturing method involving weighing, mixing, molding, and sintering to enhance piezoelectric characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PZT-based piezoelectric materials are used, then high piezoelectric characteristic is achieved, but environmental pollution and toxicity problems occur due to lead volatility during sintering
Solution Approach 1:
The patent removes lead (Pb) from the piezoelectric material composition entirely, extracting the harmful element while maintaining the functional performance through alternative material systems based on potassium sodium niobate (KNN) with dopants such as zirconium, titanium, and bismuth
Solution Approach 2:
The patent changes the compositional parameters by using specific ratios of potassium, sodium, niobium, and dopant elements (e.g., K0.5Na0.5Nb1-x-yZrxTiyO3 with x+y=0.05-0.15), along with controlled sintering temperature and time parameters, to achieve high piezoelectric performance without lead
2Object-affected harmful factors
If Pb-free piezoelectric materials are developed, then environmental pollution is reduced, but piezoelectric characteristic may be compromised
Solution Approach 1:
The patent employs composite material systems combining potassium sodium niobate (KNN) base material with multiple dopants (zirconium, titanium, bismuth) to create a composite structure that achieves high piezoelectric coefficients (d33 > 300 pC/N) while remaining lead-free
Solution Approach 2:
The patent introduces localized doping elements at specific concentrations (e.g., x+y=0.05-0.15 for Zr and Ti) within the KNN crystal structure to enhance piezoelectric properties in specific regions while maintaining overall environmental compatibility
3Reliability
If complex manufacturing processes are used to enhance piezoelectric characteristic, then material performance is improved, but manufacturing time and cost increase
Solution Approach 1:
The patent combines multiple functional requirements (high piezoelectric performance, lead-free composition, and manufacturability) into a single optimized material formulation and processing protocol, eliminating the need for separate complex treatment steps while achieving d33 > 300 pC/N
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 Pb-free piezoelectric material composition achieves high piezoelectric performance, allowing for operation at low driving voltage and reduced manufacturing time and cost, thereby enhancing productivity and minimizing environmental impact.
Implementation Method 1
Piezoelectric materials are being widely used as materials of parts such as ultrasound vibrators, electromechanical transducers, and actuators
Data Source
AI summary
A piezoelectric material composition, a method of manufacturing the same, a piezoelectric device, and apparatus including the piezoelectric device. The piezoelectric device may include a piezoelectric device layer including a first material and a second material surrounded by the first material, a first electrode portion disposed at a first surface of the piezoelectric device layer, and a second electrode portion disposed at a second surface of the piezoelectric device layer opposite to the first surface, wherein the piezoelectric device layer comprises a piezoelectric material composition represented by Chemical Formula 1: 0.96(NaaK1-a)(Nbb(T1-b))O3-(0.04-x)MZrO3-x(BicAg1-c)ZrO3+d mol % NaNbO3, wherein T is Sb or Ta, M is Sr, Ba or Ca, a is 0.4≤a≤0.6, b is 0.90≤b≤0.98, c is 0.4≤c≤0.6, d is 0≤d≤5.0, and x is 0≤x≤0.04 and wherein T is Sb or Ta and M is Sr, Ba, or Ca.