Fluid compressional properties sensing at microscale using a longitudinal bulk acoustic wave transducer operated in a pulse-echo scheme

Pulse - Echo Shear Wave Transducer

Type and size are the most important defect characteristics that need to oe determined for reliable prediction of the remaining service lifetime of a defective structure or part. The analytical and supporting experimental results presented in this paper concern a universal ultrasonic defect-identificationand-subsequent-sizing method. The conceived satellite-pulse technique (SPT) is based on the...

Porous silicon bulk acoustic wave resonator with integrated transducer

: We report that porous silicon acoustic Bragg reflectors and AlN-based transducers can be successfully combined and processed in a commercial solidly mounted resonator production line. The resulting device takes advantage of the unique acoustic properties of porous silicon in order to form a monolithically integrated bulk acoustic wave resonator.

Bulk acoustic wave resonator as a sensing platform for NOx at high temperatures

Diesel engines, generating harmful NOx, will be subjected to legislation that stipulates large reductions in emission levels beginning in 2007. For controlling emissions, a NOx sensor is needed to provide feedback to the engine management system. In this work, we take advantage of the high mass sensitivity of resonant sensors and the chemical reaction of barium carbonate (BaCO3) with NO2 gas as...

Particle Enrichment in Longitudinal Standing Bulk Acoustic Wave Microfluidics

Design and Fabrication of a Longitudinal-Torsional Ultrasonic Transducer

A hybrid longitudinal-torsional ultrasonic transducer is designed and fabricated in this research. The design of the transducer was performed using the FE method with ABAQUS software, with the aim of combining the longitudinal and torsional vibration modes. The transducer horn is then fabricated using a 4-axis milling machine. The PZT stacks are employed in order to excite the transducer. The t...