We present experimental demonstrations of negative refraction and focusing of ultrasonic waves in twodimensional phononic crystals made of stainless steel rods assembled in a triangular lattice and immersed in a liquid. Negative refraction is achieved for the range of frequencies in the second band, where the directions of the wave vector and group velocity are antiparallel to each other due to...

The inspection of complex-shaped components can suffer from the fact that the area of interest can not be properly insonified due to restricted access. In such cases, mirrors can be applied to turn the ultrasonic beam onto the component’s surface. In this paper, the optimization of such a mirror is illustrated for a specific application in aero engine inspection. Its shape has been designed to ...

We describe a numerical model initially aimed at simulating the propagation of acoustic surface waves in multilayered structures and show how it can be used to the prediction of the electric response of a non-focusing ultrasonic transducer. We also apply this model to non-destructive evaluation of the elastic properties of porous silicon.

A tactile display that provides tactile stimulation from a distance is studied. Hundreds of ultrasonic transducers cooperate to make a focal point of ultrasound based on phased-array focusing technique. It provides tactile feedback to floating images and natural user interfaces. It also tactually delivers characters, symbols, drawings, etc. to users.

Non-invasive, focal neurostimulation with ultrasound is a potentially powerful neuroscientific tool that requires effective transcranial focusing of ultrasound to develop. Time-reversal (TR) focusing using numerical simulations of transcranial ultrasound propagation can correct for the effect of the skull, but relies on accurate simulations. Here, focusing requirements for ultrasonic neurostimu...

High resolution ultrasonic imaging requires high frequency wide band ultrasonic transducers, which produce short pulses and highly focused beam. However, currently the frequency of ultrasonic transducers is limited to below 100 MHz, mainly because of the challenge in precise control of fabrication parameters. This paper reports the design, fabrication, and characterization of sensitive broadban...