Miniature conical transducer realized by excimer laser micro-machining technique

This paper presents the fabrication and characterization of a miniature con ical transducer that can be used as an acoustic emission sensor for localiz ed measurements. The development of the miniature conical transducer is bas ed on the commercial NBS conical transducer and the micro-fabrication capab ility of an excimer laser. The conical PZT element, which is the key compon ent in the transducer, is fabricated by an excimer laser micro-machining wo rkstation with a specially designed laser mask and a new work piece rotatio n machining technique. Small conical piezoelectric elements with end surfac e around 200 mum in diameter are directly fabricated out of a polarized PZT ceramic plate. The miniature conical transducer is then constructed. Stand ard acoustic emission measurements are carried out to characterize the perf ormance of the transducer. Very good results are observed which indicate th at the miniature conical transducer can be successfully used for measuring high-frequency dynamic surface motion. (C) 2001 Elsevier Science B.V. All r ights reserved.