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This paper presents a resonant-driving piezoelectric micro-cantilever for application to the ultrasound source, which can provide sufficient ultrasound energy in liquid environment by actuating maximally at the cantilever's resonant frequency. The compact-sized microcantilevers were firstly designed to be operated in deionized water solution in this paper with consideration of its further application to intravascular catheter-delivered transducertipped ultrasound thrombolysis devices as the ultrasound energy source. The micro-cantilever models, which have the target resonant frequencies of *40 kHz in DI water, were designed on the basis of numerical calculations, finite element method analysis and pre-experiment results based on the measured resonant frequencies in air, and fully fabricated by micromachining technologies. The resonant frequencies in DI water for each cantilever model were measured to be 10.94, 23.14, 33.1, and 44.02 kHz which are matched excellently with the targeted frequencies of 10, 20, 30 and 40 kHz, respectively. In addition, we could experimentally observe that red blood cells aggregated locally in 5% diluted blood solution were rapidly disaggregated within a few seconds by sufficient ultrasound energy generated by resonant-actuations of the proposed micro-cantilever.

This article reports on a low temperature cofired ceramic (LTCC)‐based RF MEMS packaging and its electrical modeling using lumped elements and microstrip lines. An LTCC cap with vertical vias was flip‐chip bonded with a glass substrate, where a coplanar waveguide (CPW) formed to measure the RF characteristics of packaging structure. We measured return loss (S11) and insertion loss (S21) of the fabricated packaging structure in a frequency range of 1 to 30 GHz. The parameters of two different equivalent circuits using lumped elements and physical microstrip lines were extracted from the measured results. The mean absolute errors (MAEs) were calculated to show the agreement between measured properties and electrical equivalent circuits. The calculated MAEs were 0.591 dB (S11) and 0.146 dB (S21) for lumped elements, and 0.926 dB (S11) and 0.179 dB (S21) for microstrip lines, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 252–257, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24895