We report on the development of transducers for ultrasonic flaw detection which can be permanently mounted at critical locations on structures. We will show that MEMS capacitive diaphragm transducers can be bonded to metal or plexiglas test speciments without damage and that ultrasonic energy can be efficiently coupled into the transducer. It will be demonstrated that transducer arrays can be o...

Piezoelectric single crystals, which have excellent piezoelectric properties, have extensively been employed for various sensors and actuators applications. In this paper, the state-of-art in piezoelectric single crystals for ultrasonic transducer applications is reviewed. Firstly, the basic principles and design considerations of piezoelectric ultrasonic transducers will be addressed. Then, th...

We describe the construction of an ultrasonic device capable of micro-patterning a range of microscopic particles for bioengineering applications such as targeted drug delivery. The device is formed from seven ultrasonic transducers positioned around a heptagonal cavity. By exciting two or three transducers simultaneously, lines or hexagonal shapes can be formed with microspheres, emulsions and...

development of ultrasound technique has not been progressing for evaluating the internal quality of fruits as fast as that of processed foods. in this research for quality assessment of pear fruit (shah miveh variety) an ultrasonic measurement system was constructed to transmit and receive the ultrasonic waves. the apparatus included a pulser-receiver, a pair of 75 khz ultrasonic transducers wi...

Indoor ultrasonic location systems provide fine-grained position data to ubiquitous computing applications. However, the ultrasonic location systems previously developed utilize narrowband transducers, and thus perform poorly in the presence of noise and are constrained by the fact that signal collisions must be avoided. In this paper, we present a novel ultrasonic location system which utilize...

Interface Electronics for Ultrasonic Transducers by Hao-Yen Tang Doctor of Philosophy in Engineering Electrical Engineering and Computer Sciences University of California, Berkeley Professor Bernhard E. Boser, Chair Ultrasound has long been used for medical imaging. Recent advances of miniaturized MEMS ultrasonic transducers new applications such as gesture recognition, personal fitness devices...

Ultrasonic methods are widely applied for nondestructive evaluation of structural components during both the manufacturing process and subsequent field inspections. The field inspections often require expensive teardown in order to access the back surfaces of critical components. Active ultrasonic methods are also a subject of ongoing research for structural health monitoring whereby transducer...