Limits...
Manipulation of acoustic focusing with an active and configurable planar metasurface transducer.

Zhao J, Ye H, Huang K, Chen ZN, Li B, Qiu CW - Sci Rep (2014)

Bottom Line: It has a pivotal role in medical science and in industry to concentrate the acoustic energy created with piezoelectric transducers (PTs) into a specific area.Furthermore, there is to date no such design method of PTs that allows a large degree of freedom to achieve designed focal patterns.Our approach may offer more initiatives where the strict control of acoustic high-energy areas is demanding.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Republic of Singapore [2] Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117546, Republic of Singapore.

ABSTRACT
It has a pivotal role in medical science and in industry to concentrate the acoustic energy created with piezoelectric transducers (PTs) into a specific area. However, previous researches seldom consider the focal resolution, whose focal size is much larger than one wavelength. Furthermore, there is to date no such design method of PTs that allows a large degree of freedom to achieve designed focal patterns. Here, an active and configurable planar metasurface PT prototype is proposed to manipulate the acoustic focal pattern and the focal resolution freely. By suitably optimized ring configurations of the active metasurface PT, we demonstrate the manipulation of focal patterns in acoustic far fields, such as the designed focal needle and multi foci. Our method is also able to manipulate and improve the cross-sectional focal resolution from subwavelength to the extreme case: the deep sub-diffraction-limit resolution. Via the acoustic Rayleigh-Sommerfeld diffraction integral (RSI) cum the binary particle swarm optimization (BPSO), the free manipulation of focusing properties is achieved in acoustics for the first time. Our approach may offer more initiatives where the strict control of acoustic high-energy areas is demanding.

No MeSH data available.


Related in: MedlinePlus

The radial distribution of the normalized squared absolute pressure at the cross section z = 20.06λ on the left, showing the focal size of the far-field acoustic super-oscillatory super resolution.On the right is the corresponding field distribution of the squared absolute pressure.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4150112&req=5

f4: The radial distribution of the normalized squared absolute pressure at the cross section z = 20.06λ on the left, showing the focal size of the far-field acoustic super-oscillatory super resolution.On the right is the corresponding field distribution of the squared absolute pressure.

Mentions: Our design method, the acoustic RSI cum BPSO in terms of PT technology, is able to manipulate the acoustic focal resolution as well and to increase it to the acoustic super-oscillatory super resolution. In this case, we choose V0 = 100V and f = 40 kHz for the electric potential exerted on all PZT-5H rings, which produce acoustic waves of λ = 8.575 mm in air. After setting the acoustic super-oscillatory super resolution (FWHM = 0.3λ at z = 20.06λ) as the designed focal resolution, we simultaneously optimize the ring configuration of the active metasurface PT in the same say, which includes 19 PZT-5H rings as shown in Supplementary Information, while q = 2 mm is adopted here optimally. The optimized result is the orange dashed curve in Fig. 4, showing the designed radial distribution of the normalized /p(r,ω)/2 at z = 20.06λ. The blue curve shows the corresponding full-wave simulation. The field distribution of the squared absolute pressure at the same cross section is plotted on the right in Fig. 4 to exhibit the result of the focal-resolution manipulation.


Manipulation of acoustic focusing with an active and configurable planar metasurface transducer.

Zhao J, Ye H, Huang K, Chen ZN, Li B, Qiu CW - Sci Rep (2014)

The radial distribution of the normalized squared absolute pressure at the cross section z = 20.06λ on the left, showing the focal size of the far-field acoustic super-oscillatory super resolution.On the right is the corresponding field distribution of the squared absolute pressure.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150112&req=5

f4: The radial distribution of the normalized squared absolute pressure at the cross section z = 20.06λ on the left, showing the focal size of the far-field acoustic super-oscillatory super resolution.On the right is the corresponding field distribution of the squared absolute pressure.
Mentions: Our design method, the acoustic RSI cum BPSO in terms of PT technology, is able to manipulate the acoustic focal resolution as well and to increase it to the acoustic super-oscillatory super resolution. In this case, we choose V0 = 100V and f = 40 kHz for the electric potential exerted on all PZT-5H rings, which produce acoustic waves of λ = 8.575 mm in air. After setting the acoustic super-oscillatory super resolution (FWHM = 0.3λ at z = 20.06λ) as the designed focal resolution, we simultaneously optimize the ring configuration of the active metasurface PT in the same say, which includes 19 PZT-5H rings as shown in Supplementary Information, while q = 2 mm is adopted here optimally. The optimized result is the orange dashed curve in Fig. 4, showing the designed radial distribution of the normalized /p(r,ω)/2 at z = 20.06λ. The blue curve shows the corresponding full-wave simulation. The field distribution of the squared absolute pressure at the same cross section is plotted on the right in Fig. 4 to exhibit the result of the focal-resolution manipulation.

Bottom Line: It has a pivotal role in medical science and in industry to concentrate the acoustic energy created with piezoelectric transducers (PTs) into a specific area.Furthermore, there is to date no such design method of PTs that allows a large degree of freedom to achieve designed focal patterns.Our approach may offer more initiatives where the strict control of acoustic high-energy areas is demanding.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Republic of Singapore [2] Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117546, Republic of Singapore.

ABSTRACT
It has a pivotal role in medical science and in industry to concentrate the acoustic energy created with piezoelectric transducers (PTs) into a specific area. However, previous researches seldom consider the focal resolution, whose focal size is much larger than one wavelength. Furthermore, there is to date no such design method of PTs that allows a large degree of freedom to achieve designed focal patterns. Here, an active and configurable planar metasurface PT prototype is proposed to manipulate the acoustic focal pattern and the focal resolution freely. By suitably optimized ring configurations of the active metasurface PT, we demonstrate the manipulation of focal patterns in acoustic far fields, such as the designed focal needle and multi foci. Our method is also able to manipulate and improve the cross-sectional focal resolution from subwavelength to the extreme case: the deep sub-diffraction-limit resolution. Via the acoustic Rayleigh-Sommerfeld diffraction integral (RSI) cum the binary particle swarm optimization (BPSO), the free manipulation of focusing properties is achieved in acoustics for the first time. Our approach may offer more initiatives where the strict control of acoustic high-energy areas is demanding.

No MeSH data available.


Related in: MedlinePlus