Piezoelectric Micromechanical Energy Harvester Multi-Plane Vibration Capture
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Solution Overview
Problem
Conventional energy harvesters are limited by their single-degree-of-freedom systems, which restrict their ability to efficiently capture and convert low-frequency ambient mechanical energy into higher frequency electrical energy, and they often require upconversion techniques to improve efficiency, but these methods are not always effective due to the unpredictability of the input energy plane.
Innovation Solution
The development of micromechanical energy harvesters that incorporate a proof mass and a transducer with piezoelectric material, where the proof mass is accelerated to transfer kinetic energy to the transducer, causing it to vibrate at a resonance frequency, thereby upconverting the energy to a higher frequency, and these systems can operate in multiple planes to capture energy from various directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional single-degree-of-freedom energy harvesters are used, then the device structure is simple, but the energy harvesting efficiency is limited due to narrow frequency band operation
Solution Approach 1:
The energy harvester is divided into two independent degrees of freedom: in-plane motion (for capturing horizontal vibrations) and out-of-plane motion (for capturing vertical vibrations). Each DOF has its own proof mass and transducer assembly, allowing independent optimization of resonance frequencies and harvesting efficiency for different vibration directions without increasing overall system complexity
Solution Approach 2:
The invention transitions from single-plane (1D) vibration harvesting to multi-plane (3D) vibration harvesting by adding both in-plane and out-of-plane transducers. This dimensional expansion allows the device to capture energy from vibrations occurring in any direction, significantly broadening the effective operating frequency band while maintaining a compact structure
2Productivity
If upconversion techniques are used to convert low-frequency ambient energy to higher frequency output, then energy harvesting efficiency improves, but the effectiveness is reduced due to unpredictability of input energy plane
Solution Approach 1:
The energy harvester is designed with universal capability to capture vibrations from any direction by incorporating both in-plane and out-of-plane transducers. Each transducer type is optimized for its specific motion plane, but together they provide comprehensive coverage of all possible vibration directions, making the system universally effective regardless of the unpredictable nature of ambient vibrations
Solution Approach 2:
The system dynamically adapts to incoming vibration directions through its dual-DOF structure. When vibrations occur in the in-plane direction, the in-plane transducer activates; when out-of-plane vibrations occur, the out-of-plane transducer activates. This dynamic response allows the system to maintain high conversion efficiency across varying and unpredictable input conditions
3Productivity
If single-plane energy harvesters are used, then the device is easier to manufacture, but the energy capture capability is limited to one direction
Solution Approach 1:
The invention merges in-plane and out-of-plane energy harvesting capabilities into a single integrated device structure. Both transducer assemblies share common mounting substrates and electrical connection pathways, allowing multi-directional energy capture functionality to be manufactured as one unified component rather than separate assemblies, thereby maintaining ease of manufacture while enhancing energy capture capability
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
This approach enhances energy harvesting efficiency by converting low-frequency ambient mechanical energy into higher frequency electrical energy, improving power output and allowing for energy capture in multiple planes, making it suitable for integration with RF resonators and sensors.
Implementation Method 1
a transducer (e.g., piezoelectric material) and a transfer mechanism
Implementation Method 2
causing the transducer to vibrate at the resonance frequency
Data Source
AI summary
The present invention comprises systems, apparatuses, and methods for harvesting ambient mechanical energy at a lower frequency and transforming the harvested energy into electrical energy at a higher frequency. Transforming the energy from relatively lower input frequency energy to relatively higher output frequency energy can help realize greater efficiencies found at higher frequencies. Because the input plane of the ambient mechanical energy is not always predictable, some embodiments of the present invention comprise both in-plane and out-of-plane energy harvesters that produce an electrical output in multiple planes.