Multi-Stable Piezoelectric Shell for Broadband Vibration Harvesting
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Solution Overview
Problem
Existing vibration energy harvesters face challenges with variable vibration frequencies, as linear harvesters have low efficiency outside fixed frequencies and nonlinear harvesters have complex structures and high energy consumption, while bistable harvesters suffer from complex manufacturing and uncontrollable deformation.
Innovation Solution
A multi-stable shell with bistable regions and piezoelectric elements that switch between stable configurations under vibration, allowing for nonlinear motion and broadband energy absorption, enabling efficient energy conversion and design flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If linear vibration energy harvester is used, then energy conversion efficiency is high at fixed frequency, but energy absorption effect is greatly reduced when vibration frequency changes
Solution Approach 1:
The patent employs a nonlinear vibration energy harvester with adjustable parameters that can dynamically adapt to different vibration frequencies. The system transitions from a fixed-frequency linear resonant system to a nonlinear system where the natural frequency can be tuned and adjusted, allowing the harvester to maintain high energy conversion efficiency across a broader frequency range by matching the excitation frequency through parameter adjustment.
Solution Approach 2:
The patent changes the physical parameters of the vibration energy harvesting system, specifically introducing nonlinear characteristics through adjustable parameters. By modifying the system's stiffness, mass distribution, or geometric configuration, the natural frequency and bandwidth of the harvester are adjusted to accommodate variable vibration frequencies, thereby resolving the contradiction between efficiency at fixed frequency and adaptability to frequency changes.
2Adaptability or versatility
If nonlinear vibration energy harvester is used, then working frequency range is wide and energy conversion efficiency is high, but structure becomes complex and energy consumption increases
Solution Approach 1:
The patent introduces local nonlinear elements into specific regions of the vibration energy harvesting structure rather than making the entire system complex. By concentrating nonlinear characteristics in localized components (such as nonlinear springs, asymmetric mass distributions, or geometric nonlinearities in specific joints), the system achieves wide frequency range while keeping the overall structure relatively simple and manageable.
3Adaptability or versatility
If bistable vibration energy harvester is used, then frequency adaptability is improved, but manufacturing complexity and deformation control become difficult
Solution Approach 1:
The patent segments the vibration energy harvesting structure into modular components, where nonlinear or bistable characteristics are isolated to specific segments rather than requiring the entire structure to be complex. This segmentation allows for easier manufacturing of individual components and simplifies deformation control, as each module can be independently fabricated and assembled, reducing overall manufacturing complexity while maintaining frequency adaptability.
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 achieves higher energy conversion efficiency and broader frequency compatibility, making it suitable for scenarios with variable vibration frequencies and simplifying manufacturing and deformation control.
Implementation Method 1
utilizing piezoelectric material to convert the deformation energy generated by vibration into electrical energy
Data Source
AI summary
A vibration energy harvester, a power accumulator and a power supplier, including: a multi-stable shell with one or more bistable regions and at least one piezoelectric element fixed on a surface of the multi-stable shell. Each of the bistable regions has two different stable configurations, and different combinations of the stable configurations of the one or more bistable regions make the multi-stable shell have a plurality of different stable configurations. The one or more bistable regions are switched between the two stable configurations thereof when being excited by vibration energy, so that the multi-stable shell is switched between the plurality of stable configurations to deform the piezoelectric element to generate electric energy.