Twisted Nanofiber Yarn Harvesters for Higher Power Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mechanical energy harvesters, including twistron devices, face challenges in achieving high gravimetric electrical power generation and energy conversion efficiencies, particularly at specific frequency ranges and under varying mechanical strains.
Innovation Solution
The integration of conducting nanosheets into twistron yarn corridors, optimized alignment of precursor CNT forests, plastic stretching of precursor twisted yarns, application of higher tensile loads during pre-coiling twist, and utilization of the incandescence tension anneal process (ITAP) to enhance electrothermal pulse annealing under tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional electromagnetic generators are used, then they can meet many power needs, but they suffer from low power densities and high cost per Watt when scaled to millimeter and smaller dimensions
Solution Approach 1:
The patent replaces electromagnetic generators with a mechanical energy harvester based on twistron yarns that convert mechanical deformation directly into electrical energy through electrochemical capacitance changes. This substitution eliminates the need for complex electromagnetic components at small scales, achieving high power density in millimeter-scale devices.
Solution Approach 2:
The patent changes the operating parameters by using electrochemical capacitance instead of electromagnetic induction, enabling the device to achieve high power density at small dimensions. The capacitance-based mechanism allows scaling to millimeter dimensions without the power density losses inherent in electromagnetic systems.
2Adaptability or versatility
If piezoelectric and ferroelectric harvesters are used, then they work well for high-frequency, low-strain deformations, but they lack the elasticity needed for harvesting energy from large tensile strains
Solution Approach 1:
The patent uses composite materials including elastomeric sheets, conducting polymers, and nanofiber yarns embedded in flexible substrates. This composite structure provides both the elasticity needed for large tensile strains and the piezoelectric/ferroelectric properties for high-frequency response, combining the advantages of both material types.
Solution Approach 2:
The patent employs dynamically adaptable materials that can respond to both high-frequency vibrations and large static deformations. The elastomeric substrate provides dynamic flexibility for high-frequency response while allowing large tensile strains, enabling the harvester to adapt to varying deformation conditions.
3Power
If electrostatic harvesters based on triboelectric charge are used, then they provide remarkable performance, but they require future development for practical applications
Solution Approach 1:
The patent introduces an electrochemical intermediary layer between the triboelectric surfaces that stabilizes charge transfer and reduces degradation. This intermediary mechanism improves reliability by preventing direct contact wear and chemical degradation, making triboelectric harvesters ready for practical applications.
Solution Approach 2:
The patent modifies the operating parameters by using electrochemical reactions to enhance triboelectric charge generation. This changes the charge transfer mechanism from purely mechanical contact to an electrochemically assisted process, improving both power output and stability for practical applications.
4Power
If various types of electrochemically-based mechanical energy harvesters are used, then they are available including conducting polymer harvesters, lithium-battery-based bending harvesters, and IPMC harvesters, but they have not provided competitive performance
Solution Approach 1:
The patent segments the electrochemical harvester into distinct functional components: twistron yarns for mechanical-to-electrical conversion, electrolyte layers for ion transport, and electrode structures for charge collection. This segmentation allows optimization of each component for its specific function, achieving high gravimetric power generation and energy conversion efficiency.
Solution Approach 2:
The patent changes the electrochemical parameters by using novel electrolyte compositions and electrode materials that enhance capacitance and reduce resistance. These parameter changes improve both the power output and energy conversion efficiency compared to previous electrochemical harvesters.
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 significantly enhances the peak output power and energy conversion efficiency of twistron harvesters, achieving 15- and 13-fold increases in peak output power at 1 Hz and 30 Hz, respectively, compared to previous twistron harvesters, and a maximum energy conversion efficiency 7.2-fold higher than previous twistrons.
Implementation Method 1
The electrochemical capacitance changes that produce electricity result from mechanically generated changes in yarn twist. Increasing yarn twist increases yarn density, compressing and partially eliminating the electrochemical double layers of CNTs, and twist release reverses this.
Implementation Method 2
Yarn energy harvesters containing conducting nanomaterials, which yarn energy harvesters that can electrochemically convert the energy change of tensile or torsional deformations directly into electrical energy.
Implementation Method 3
When stretched, the Poisson's ratio causes the rubber dielectric to decrease thickness, thereby increasing capacitance (C). A stress-induced capacitance change (ΔC) produces a voltage change, according to Q=CV, which enables efficient harvesting of electrical energy.
Implementation Method 4
utilization of the incandescence tension anneal process (ITAP) to enhance electrothermal pulse annealing under tension
Implementation Method 5
application of higher tensile loads during pre-coiling twist, and utilization of the incandescence tension anneal process (ITAP) to enhance electrothermal pulse annealing under tension
Data Source
AI summary
Improved electrochemical yarn energy harvesters that convert mechanical energy to electrical energy. These harvesters include an ionically conducting electrolyte, and an electronically conducting material, and a material that can undergo charge injection, which can also be the electronically conducting material. At least one device electrode is either twisted, twisted and coiled, or twisted and plied.