Experimental evaluation of targeting accuracy of an ultrasound-guided phased-array high-intensity focused ultrasound system

Li, Ké; Bai, Jing; Chen, Yazhu; Ji, Xiang

doi:10.1016/j.apacoust.2018.06.011

Cited by 9 publications

(1 citation statement)

References 29 publications

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“…However, such surfaces are usually fabricated through macromachining techniques, including milling and heat pressing, whose limited precision may lead to fabrication defects, including surface roughness and curvature error. Alternatively, acoustic waves could be focused by programming the time delay of the driving signal applied on each transducer element in a phased array 14 , 15 . Through this approach, the focal position and acoustic beam direction can be precisely and dynamically controlled.…”

Section: Introductionmentioning

confidence: 99%

Simple sacrificial-layer-free microfabrication processes for air-cavity Fresnel acoustic lenses (ACFALs) with improved focusing performance

Tang

Kim

2022

Microsyst Nanoeng

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Focused ultrasound (FUS) is a powerful tool widely used in biomedical therapy and imaging as well as in sensors and actuators. Conventional focusing techniques based on curved surfaces, metamaterial structures, and multielement phased arrays either present difficulties in massively parallel manufacturing with high precision or require complex drive electronics to operate. These difficulties have been addressed by microfabricated self-focusing acoustic transducers (SFATs) with Parylene air-cavity Fresnel acoustic lenses (ACFALs), which require a time-demanding step in removing the sacrificial layer. This paper presents three new and improved types of ACFALs based on polydimethylsiloxane (PDMS), an SU-8/PDMS bilayer, and SU-8, which are manufactured through simple sacrificial-layer-free microfabrication processes that are two to four times faster than that for the Parylene ACFALs. Moreover, by studying the effect of the lens thickness on the acoustic transmittance through the lens, the performance of the transducers has been optimized with improved thickness control techniques developed for PDMS and SU-8. As a result, the measured power transfer efficiency (PTE) and peak output acoustic pressure are up to 2.0 and 1.8 times higher than those of the Parylene ACFALs, respectively. The simple microfabrication techniques described in this paper are useful for manufacturing not only high-performance ACFALs but also other miniaturized devices with hollow or suspended structures for microfluidic and optical applications.

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Section: Introductionmentioning

confidence: 99%