Sound absorbing structure including nanofibers

1. A sound absorbing structure, comprising:

at least one sound-permeable nanofiber layer with first patterns, the sound-permeable nanofiber layer comprising at least one of a patterned porosity and a random porosity, the sound-permeable nanofiber layer comprising a plurality of nanofibers configured to absorb low frequency sounds with a frequency less than 1800 Hz;

at least one sound absorbing layer directly attached to the sound-permeable nanofiber layer; and

a patterned member directly attached to the sound absorbing layer opposite the sound-permeable nanofiber layer,

wherein the patterned member comprises second patterns that corresponds to first patterns of the at least one sound-permeable nanofiber layer, and wherein the patterned member includes a reticulated pattern, a spotted pattern, a perforated pattern, and a stapled pattern.

2. The sound absorbing structure according to claim 1 , wherein the patterned member is made of an electrical conductive, the electrical conductive comprising one of a metal material, a semi-conductor material, a non-metal material, and combinations thereof.

3. The sound absorbing structure according to claim 1 , wherein the sound-permeable nanofiber layer comprises the plurality of nanofibers configured to absorb the low frequency sounds with a coefficient of sound absorption of at least 0.3.

4. The sound absorbing structure according to claim 1 , wherein the patterned porosity or the random porosity is selected from the group consisting of a perforated porosity, a spotted porosity, a stapled porosity, a reticulated porosity, and combinations thereof.

5. The sound absorbing structure according to claim 1 , wherein the sound-permeable nanofiber layer has a thickness of at least 1 nanometer.

6. The structure according to claim 1 , wherein the sound-permeable nanofiber layer includes nanofibers with a diameter of at least 1 nanometer.

7. The structure according to claim 6 , wherein the nanofibers have a cross section that is circular, trilobal, pentalobal, octalobal, elliptical, semicircular, core and shelf, porous, dumbbell-shaped, hollow fibers, or diamond-shaped.

8. The structure according to claim 1 , wherein the sound-permeable nanofiber layer is made of polymers, ceramics, nanostructures, metals, or combinations thereof.

9. The structure according to claim 8 , wherein the polymers are one of natural polymers, artificial polymers, copolymers, polyacrylonitrile (PAN), polyamide, polyester, polyethylene terephthalate (PET), cellulose acetate, Nylon 6 (PA6), Nylon 6-6, polyurethane (PU), polycarbonate (PC), polyvinyl alcohol (PVA), poly lactic acid (PLA), polyethylene oxide (PEO), polystyrene (PS), polyethylene methacrylate (PMMA), polyvinyl phenol (PVP), polyvinyl chloride (PVC), cellulose acetate (CA), PLGA, collagen, poly caprolactone (PCL), poly caprolactam, silicon rubber, and combinations thereof.

10. The structure according to claim 8 , wherein the nanostructures are one of carbon nanotube (CNT), nanoclay, nanosilica, titanium dioxide, iron(III) oxide, graphene oxide nanoparticles, gold nanoparticles, silver nanoparticles, and combinations thereof.

11. The structure according to claim 8 , wherein the ceramics are one of oxides, nitrides, carbides, and combinations thereof.

12. The structure according to claim 8 , wherein the metals are one of silver, gold, iron, tungsten, and combinations thereof.

13. The sound absorbing structure according to claim 1 , wherein the sound absorbing layer is made of rock wool, glass wool, foam, cloth, paper, wood, metal, and combinations thereof.

14. The sound absorbing structure according to claim 1 , wherein the sound absorbing layer comprises a non-woven fabric, a woven fabric, a knitted fabric, a spun-bonded fabric, a melt-blown fabric, a needle-punched fabric, an apertured web, a split film web, a hydro-entangled web, an adhesive-backed web, an air-laid staple fiber web, an elastic fabric web, a mesh, a porous web, or combinations thereof.

15. The sound absorbing structure according to claim 1 , wherein the sound absorbing layer has a thickness of at least 1 nanometer.

16. A method for fabricating a sound absorbing structure, comprising:

providing a sound absorbing layer;

attaching an electroconductive patterned member to the sound absorbing layer; and

electrospinning a plurality of nanofibers directly on the sound absorbing layer or on the electroconductive patterned member to form a sound-permeable nanofiber layer with a patterned porosity corresponding to a pattern of the electroconductive patterned member.

17. The method according to claim 16 , wherein the plurality of nanofibers are synthesized through an electrostatic spinning process, which is selected from the group consisting of bubble electrospinning, melt electrospinning, magnetic electrospinning, nozzle-less electrospinning, centrifugal electrospinning, coaxial electrospinning, classic electrospinning, gas jacket electrospinning, continuous electrospinning, and combinations thereof.

18. A method for fabricating a sound absorbing structure, comprising:

providing a sound absorbing layer;

depositing a plurality of nanofibers on the sound absorbing layer to form a nanofiber layer attached to the sound absorbing layer;

increasing the sound permeability of the nanofiber layer to form a sound-permeable nanofiber layer attached to the sound absorbing layer; and

directly attaching a patterned member to the sound absorbing layer opposite the sound-permeable nanofiber layer.

19. The method according to claim 18 , wherein the plurality of nanofibers are synthesized through one of electrostatic spinning, force spinning, phase separation, flash spinning, self-assembly, template synthesis, sol-gel, matrix/fibril, wet spinning, interfacial spinning, electrospinning, and combinations thereof.

20. The method according to claim 18 , wherein the plurality of nanofibers are synthesized through one of bubble electrospinning, melt electrospinning, magnetic electrospinning, nozzle-less electrospinning, centrifugal electrospinning, coaxial electrospinning, classic electrospinning, gas jacket electrospinning, continuous electrospinning, and combinations thereof.

21. The method according to claim 18 , wherein the sound permeability of the nanofiber layer is increased during the nanofiber layer formation, or after the nanofiber layer formation, or combinations thereof.

22. The method according to claim 21 , wherein the sound permeability of the nanofiber is increased during the formation of the nanofiber layer through formation of the nanofiber layer with two different types of nanofibers and subsequently removing one type of the nanofibers, formation of the nanofiber layer in a three-dimensional manner by using nanoparticles and micro particles, formation of the nanofiber layer by using nanofibers with different diameters, salt bleaching method, collecting the synthesized nanofibers far away each other, and combinations thereof.

23. The method according to claim 21 , wherein the sound permeability of the nanofiber is increased after the formation of the nanofiber layer through using an ultrasonic device, using a laser light radiation device, or combinations thereof.