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High-sensitivity acoustic sensors from nanofibre webs

View Article: PubMed Central - PubMed

ABSTRACT

Considerable interest has been devoted to converting mechanical energy into electricity using polymer nanofibres. In particular, piezoelectric nanofibres produced by electrospinning have shown remarkable mechanical energy-to-electricity conversion ability. However, there is little data for the acoustic-to-electric conversion of electrospun nanofibres. Here we show that electrospun piezoelectric nanofibre webs have a strong acoustic-to-electric conversion ability. Using poly(vinylidene fluoride) as a model polymer and a sensor device that transfers sound directly to the nanofibre layer, we show that the sensor devices can detect low-frequency sound with a sensitivity as high as 266 mV Pa−1. They can precisely distinguish sound waves in low to middle frequency region. These features make them especially suitable for noise detection. Our nanofibre device has more than five times higher sensitivity than a commercial piezoelectric poly(vinylidene fluoride) film device. Electrospun piezoelectric nanofibres may be useful for developing high-performance acoustic sensors.

No MeSH data available.


Material and characterization.(a) SEM image of the PVDF nanofibres (scale bar, 1 μm), (b) schematic illustration of sensor structure, (c) digital photo of the device (scale bar, 1 cm), (d) schematic illustration of the setup for testing the sensor device, (e) illustration of sound wave (the black dots illustrate the motion of air molecules associated with sound), (f) voltage outputs of the device under sound with and without FFT treatment (hole diameter, 12.8 mm; web thickness, 40 μm; web area, 12 cm2).
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f1: Material and characterization.(a) SEM image of the PVDF nanofibres (scale bar, 1 μm), (b) schematic illustration of sensor structure, (c) digital photo of the device (scale bar, 1 cm), (d) schematic illustration of the setup for testing the sensor device, (e) illustration of sound wave (the black dots illustrate the motion of air molecules associated with sound), (f) voltage outputs of the device under sound with and without FFT treatment (hole diameter, 12.8 mm; web thickness, 40 μm; web area, 12 cm2).

Mentions: PVDF nanofibres were prepared by a needle electrospinning technique. Figure 1a shows the morphology of the as-electrospun fibres. All fibres looked uniform without bead. The fibres had a diameter of 310±60 nm (see the histogram of diameter distribution in Supplementary Fig. 1). The X-ray diffraction pattern and Fourier transform infrared spectrum indicated that the PVDF nanofibres mainly contained α and β crystal phases, with the β-phase content as high as 86% (see the detail calculation in Supplementary Fig. 2). These results are in good accordance with our previous findings1621, and the high β-phase content is beneficial to mechanical-to-electronic energy conversion25.


High-sensitivity acoustic sensors from nanofibre webs
Material and characterization.(a) SEM image of the PVDF nanofibres (scale bar, 1 μm), (b) schematic illustration of sensor structure, (c) digital photo of the device (scale bar, 1 cm), (d) schematic illustration of the setup for testing the sensor device, (e) illustration of sound wave (the black dots illustrate the motion of air molecules associated with sound), (f) voltage outputs of the device under sound with and without FFT treatment (hole diameter, 12.8 mm; web thickness, 40 μm; web area, 12 cm2).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4814578&req=5

f1: Material and characterization.(a) SEM image of the PVDF nanofibres (scale bar, 1 μm), (b) schematic illustration of sensor structure, (c) digital photo of the device (scale bar, 1 cm), (d) schematic illustration of the setup for testing the sensor device, (e) illustration of sound wave (the black dots illustrate the motion of air molecules associated with sound), (f) voltage outputs of the device under sound with and without FFT treatment (hole diameter, 12.8 mm; web thickness, 40 μm; web area, 12 cm2).
Mentions: PVDF nanofibres were prepared by a needle electrospinning technique. Figure 1a shows the morphology of the as-electrospun fibres. All fibres looked uniform without bead. The fibres had a diameter of 310±60 nm (see the histogram of diameter distribution in Supplementary Fig. 1). The X-ray diffraction pattern and Fourier transform infrared spectrum indicated that the PVDF nanofibres mainly contained α and β crystal phases, with the β-phase content as high as 86% (see the detail calculation in Supplementary Fig. 2). These results are in good accordance with our previous findings1621, and the high β-phase content is beneficial to mechanical-to-electronic energy conversion25.

View Article: PubMed Central - PubMed

ABSTRACT

Considerable interest has been devoted to converting mechanical energy into electricity using polymer nanofibres. In particular, piezoelectric nanofibres produced by electrospinning have shown remarkable mechanical energy-to-electricity conversion ability. However, there is little data for the acoustic-to-electric conversion of electrospun nanofibres. Here we show that electrospun piezoelectric nanofibre webs have a strong acoustic-to-electric conversion ability. Using poly(vinylidene fluoride) as a model polymer and a sensor device that transfers sound directly to the nanofibre layer, we show that the sensor devices can detect low-frequency sound with a sensitivity as high as 266 mV Pa−1. They can precisely distinguish sound waves in low to middle frequency region. These features make them especially suitable for noise detection. Our nanofibre device has more than five times higher sensitivity than a commercial piezoelectric poly(vinylidene fluoride) film device. Electrospun piezoelectric nanofibres may be useful for developing high-performance acoustic sensors.

No MeSH data available.