Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2301.00118

Airborne Ultrasound Focusing Aperture with Binary Amplitude Mask Over Planar Ultrasound Emissions

Masatake Kitano·Keisuke Hasegawa
View original source ↗Read source document ↗Export metadata ↓

Abstract

Phased arrays of airborne ultrasound transducers are widely utilized as a key technology to achieve mid-air convergence of intense ultrasound, which is applied to a variety of systems, such as contactless tactile presentation, acoustic-levitation and its application, mid-air-flow acceleration, etc. However, it requires considerably precise phase control with temporally severe synchronization between elements, which leads to difficulty in scaling up the entire system beyond the tabletop size as most of the current application systems. Here, we propose a much simpler and easier scaling-up method of airborne ultrasound convergence, where a binary amplitude mask that serves as a Fresnel Zone Plate (FZP) is placed on the planar in-phase ultrasound sources. We experimentally demonstrate that the FZP-based ultrasound focusing achieved a spatial resolution that is comparable to conventional methods, based on the use of phase-controlled transducers. The ultrasound foci created using FZPs are sufficiently intense for most application scenarios that are currently in practical use. We also determine favorable side effects of our method suppressing grating lobes, which is inevitable with the conventional phase-controlling method. The FZPs and planar ultrasound sources are both readily implemented with inexpensive ingredients and components. The result of our study contributes to upsizing dimensions in which a mid-air convergent ultrasound field is successfully generated. Accordingly, unprecedented application scenarios that target the entire room as the workspace will be possible.

Explore related subjects

physics.app-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Masatake Kitano, Keisuke Hasegawa. 2023-03-21. Airborne Ultrasound Focusing Aperture with Binary Amplitude Mask Over Planar Ultrasound Emissions. https://doi.org/10.1063/5.0140604

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Pendellösung length-scale neutron and X-ray interferometry

Neutron and X-ray perfect-crystal interferometers (PCIs) are powerful platforms for studies of fundamental physics and phase-contrast imaging. Further enhancing several PCI capabilities requires reducing crystal blade thickness to the micron scale, which minimizes dynamical-diffraction image blur, permits operation in the pendellösung regime where blade thickness controls beam splitting, and reduces absorption for simultaneous neutron and X-ray operation. However, fabricating multiple crystal blades with identical micrometer-scale thicknesses over centimeter-scale areas remains a major challenge. Here, using a non-etching sub-micron fabrication technique, we demonstrate silicon triple-Laue interferometers with equal-blade-thicknesses of 110 $μ$m and 350 $μ$m, operated with both neutrons and X-rays. These devices are the thinnest PCIs realized to date, enabling a factor-of-six reduction in dynamical-diffraction beam spreading for improved phase-contrast imaging, while reaching the single pendellösung length regime in which crystal thickness provides an experimentally accessible control parameter for engineered quantum-optical beam splitting of plane-wave inputs. These results motivate multi-blade PCI designs utilizing identical half-pendellösung crystal lamellae that are proposed for neutron spin--orbit and electric dipole moment measurements.

physics.app-ph↗
arXiv2026

A State-Space Framework for trivial and Topological Metamaterial Stochastic Analysis

Topological phononic crystals and elastic metamaterials support edge states defined by global topological invariants, offering a route toward vibration-control and wave-guiding devices that remain functional in the presence of defects. However, manufacturing-induced spatial variability can perturb these invariants and compromise their robustness, making its quantification essential during design. In this work, we first demonstrate that a previously proposed linear time-varying (LTV) formulation is mathematically equivalent to the spectral element method based on transfer matrices for elementary rod, Saint-Venant shaft, and Euler-Bernoulli beam theories. The deterministic formulation is then extended to stochastic analyses through a stochastic linear time-varying (SLTV) framework. The proposed methodology combines Monte Carlo simulations with stochastic Fourier series and an analytical Karhunen--Loève expansion, providing closed-form stochastic fields and their derivatives required by the LTV formulation. The SLTV approach enables the computation of stochastic dispersion diagrams and forced responses of one-dimensional waveguides with arbitrarily varying geometry and mechanical properties. Because the LTV-based transition matrix isolates individual wavemodes without requiring the mode tracking needed by conventional eigenproblem-based formulations, the framework is particularly suited for evaluating topological invariants, specifically the Zak phase, and assessing the robustness of topological bands under spatial variability. Numerical results for rods, shafts, and Euler-Bernoulli beams demonstrate the applicability of the proposed framework as a unified methodology for deterministic and stochastic analyses of trivial and topological periodic waveguides under continuous spatial uncertainty.

physics.app-ph↗
arXiv2026

Low-loss phononic integrated circuits based on a silicon nitride-lithium niobate platform

Microwave-frequency acoustic waves in solids have emerged as a versatile platform for both classical and quantum applications. While phononic integrated devices and circuits are being developed on various material platforms, an ideal phononic integrated circuit (PnIC) platform should simultaneously support low-loss waveguide structures, high-quality-factor resonators, high-performance modulators, and efficient electromechanical transducers. Here, we establish a low-loss gigahertz-frequency PnIC platform based on patterned thin-film silicon nitride (SiN) on lithium niobate (LN) substrate. We develop low-loss PnIC building blocks including waveguides, directional couplers, and high-quality-factor (high-Q) ring resonators. As an application, we demonstrate a 1-GHz phononic oscillator based on a ring resonator, reaching a low phase noise of -159.0 dBc/Hz at a 100-kHz offset frequency. Our low-loss PnICs could meet the requirements in microwave acoustics, quantum phononics, and integrated hybrid systems combining phonons, photons, superconducting qubits, and solid-state defects.

physics.app-ph↗