Reconfiguring Surface Acoustic Wave Microfluidics via In Situ Control of Elastic Wave Polarization.

We demonstrate in situ control of the elastic wave polarization in a surface acoustic wave (SAW). It allows us to create highly reconfigurable SAW microfluidics that can be switched on demand between the acoustohydrodynamic (AHD) regime and electrohydrodynamic (EHD) regime for manipulating particles and cells. The control of wave polarization comes from our experimental and theoretical identification of an unexpected shear-horizontal (SH) wave mode in a conventional Rayleigh (R) wave design, which is stereotyped to excite only vertically polarized Rayleigh SAWs.

Critical role of protein kinase CK2 in chronic myeloid leukemia cells harboring the T315I BCR::ABL1 mutation.

Chronic myeloid leukemia (CML) is characterized by the fusion protein BCR::ABL1, a constitutively active tyrosine kinase. The frontline treatment, represented by tyrosine kinase inhibitors (TKIs), has dramatically improved the clinical outcomes of patients. However, TKI resistance through various mechanisms has been reported.

A Lossless Sink Based on Complex Frequency Excitations.

The creation of a sink in a lossless wave-bearing medium is achieved using complex frequency signals-harmonic excitations that exponentially grow in time. The wave sink, where incident waves are confined to a point, has attracted interest for imaging and sensing since it may lead to arbitrarily small hotspots that surpass the diffraction limit. However, most methods of creating sinks require careful tuning, such as by impedance matching the sink to free space through the inclusion of loss, which imposes constraints on emerging applications.

Topological Surface States in a Gyroid Acoustic Crystal.

The acoustic properties of an acoustic crystal consisting of acoustic channels designed according to the gyroid minimal surface embedded in a 3D rigid material are investigated. The resulting gyroid acoustic crystal is characterized by a spin-1 Weyl and a charge-2 Dirac degenerate points that are enforced by its nonsymmorphic symmetry. The gyroid geometry and its symmetries produce multi-fold topological degeneracies that occur naturally without the need for ad hoc geometry designs.

Optimizing transcranial ultrasound delivery at large incident angles by leveraging cranial leaky guided wave dispersion.

We investigate the role of leaky guided waves in transcranial ultrasound transmission in temporal and parietal bones at large incidence angles. Our numerical and experimental results show that the dispersion characteristics of the fundamental leaky guided wave mode with longitudinal polarization can be leveraged to estimate the critical angle above which efficient shear mode conversion takes place, and below which major transmission drops can be expected. Simulations that employ a numerical propagator matrix and a Semi-Analytical approach establish the transcranial dispersion characteristics and transmission coefficients at different incident angles.