Permittivity measurement for biological application using micromachined probe

We implemented a micromachined probe for the measurement of biological properties using MEMS technology. We experimentally showed the suitability of the micromachined probe in biological applications through liquids and solid experiments. The micromachined probe consists of a CPW and strip line between benzo cyclo butene (BCB) layers because it has excellent properties such as high resistivity, low loss tangent and low permittivity at higher frequencies. The aperture size of the micromachined probe is only 650 μm × 70 μm. We measured the permittivity of a number of well- known liquids - 0.5, 0.9 and 1.3 % saline, acetone, and muscle and fat of pork - as biological samples using the micromachined probe after liquid calibration. In this paper, we first demonstrate that the micromachined probe can provide broadband measurement of measurable solid materials, such as biological samples, and also of well-known liquids at microwave frequencies.