PVDF Nanofiber Membrane for Low-Frequency Sound Absorption
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Solution Overview
Problem
Conventional sound-absorbing materials are ineffective at absorbing middle to low frequency sounds, which can cause more significant harm to human health, and there is a need for materials that can absorb a full range of frequencies.
Innovation Solution
A sound-absorbing material comprising a membrane with piezoelectric fibers, specifically PVDF electrospinning nanofibers, with a fiber density below 50 g/m² and thickness less than 1 mm, exhibiting a sound-absorbing coefficient greater than 0.1 at 100 Hz and over 0.05 at 800 Hz to 1000 Hz, which can be laminated with acoustic foam or non-woven fabric for enhanced full-frequency absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sound-absorbing materials are used, then high frequency sound absorption is improved, but middle to low frequency sound absorption deteriorates
Solution Approach 1:
The patent employs porous membrane materials with carefully controlled pore structures to absorb middle to low frequency sounds. The porous structure allows sound waves to penetrate and dissipate energy through friction and viscous effects within the pores, achieving effective absorption in the problematic frequency range while maintaining material flexibility and thinness.
Solution Approach 2:
The invention uses composite structures combining piezoelectric fibers with porous membrane materials. This composite approach leverages the piezoelectric effect for active sound wave interaction and the porous structure for passive absorption, creating a material that effectively handles both high and middle to low frequency sounds simultaneously.
2Ease of operation
If membrane thickness is reduced to increase flexibility, then ease of operation is improved, but sound absorption performance deteriorates
Solution Approach 1:
The patent utilizes thin film membrane structures with optimized thickness and material composition to maintain flexibility while achieving effective sound absorption. The thin film design allows the material to conform to various surfaces and applications, while the specialized porous structure and piezoelectric fiber integration compensate for the reduced thickness to maintain absorption performance.
Solution Approach 2:
The invention optimizes multiple material parameters including fiber density, pore size distribution, membrane thickness, and piezoelectric fiber concentration to achieve the optimal balance between flexibility and sound absorption. By carefully controlling these parameters, the material achieves high flexibility with maintained absorption coefficients across different frequency ranges.
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 material demonstrates superior sound-absorbing ability in middle to low frequencies, is thinner and more flexible than conventional materials, and can be used to create broadband sound absorbers with minimal thickness limitations, outperforming conventional sound-absorbing materials in absorption coefficients across the 100 Hz to 1000 Hz range.
Implementation Method 1
a membrane having multiple piezoelectric fibers
Implementation Method 2
sound-absorbing coefficient of the membrane is larger than 0.1 at absorbing frequency at 100 Hz
Data Source
AI summary
A sound-absorbing material has a membrane having multiple piezoelectric fibers, the fiber density of the membrane is below 50 g/m2, the thickness of the membrane is below 1 mm, sound-absorbing coefficient of the membrane is larger than 0.1 at absorbing frequency at 100 Hz+/−10%, and the sound-absorbing coefficient of the membrane is over 0.05 at absorbing frequency at 800 Hz to 1000 Hz. PVDF electrospinning nanofiber membranes of the present invention are thinner and more flexible compared to conventional sound-absorbing material, the membranes in the present invention performs excellent low frequency sound absorption with very thin membrane.