It was recently proposed that the lateral resonances around the working resonance band of ultrasonic piezoelectric sandwich transducers can be stopped by a periodic array of circular holes drilled along the main propagation direction (a phononic crystal). In this work, the performance of different transducer designs made with this procedure is tested using laser vibrometry, electric impedance t...

This paper describes the work done in an attempt to integrate ultrasonic sensors in micro-fluidic channels. We have developed a system with fluidic channels having embedded zinc oxide transducers. A zinc oxide film is deposited on a glass substrate and is sandwiched between two electrodes. The transducers made are found to resonate at 400 MHz in thickness mode. The channels are made both from P...

Because of the need of rapid detection of internal defects and embedded object in concrete structures, a ultrasonic detecting method with linear array transducers is presented here, which is the high-resolution and efficient imaging technique for concrete materials by combining with synthetic aperture focusing technique (SAFT). At first, simulation data of array detection are processed to be am...

We describe an approach for mobile robot localization based on geometric features extracted from ultrasonic data. As is well known, a single sonar measurement using a standard POLAROIDTM sensor, though yielding relatively accurate information regarding the range of a reflective surface patch, provides scant information about the location in azimuth or elevation of that patch. This lack of suffi...

This paper describes the design and testing method of a micro robotic detector. The detector was implemented with capacitors. The chip employs the concept of an ultrasonic rangefinder. The fly can detect and locate objects in all directions easily. The micro robot needs to have this capability. In order to implement this, detectors was built to resemble a “soccer ball”. A robust fabrication pro...

The maximum value of acoustic pressure within an ultrasonic beam is limited by acoustic saturation. The t oretical basis for acoustic saturation has been analyzed previously. In this work, a high-power pulse source is used to drive acoustic pressure levels from an ultrasonic beam to saturation. An automatic procedure determines the field’s beam axis using a calibrated Marconi PVDF hydrophone. T...