Improvement of sensitivity of force sensor probe using quartz crystal resonator

Measuring the mechanical properties of cells or tissues is important in the field of tissue engineering. However, previous force sensor probe using quartz crystal resonator (QCR) does not have enough sensitivity for measuring single cell and living membrane tissue. In this study, we present high sensitive force sensor probe using QCR. The key for improvement of resolution of QCR force sensor probe is the thickness of QCR. By using wet etching technique, we succeeded in decreasing the thickness of QCR from 41.7 to 15 μm. We evaluated the performance of fabricated QCR force sensor probe. The sensitivity and time stability were 712,888 Hz/N and 0.52 Hz, respectively. From these results, we achieved that the measurable minimum force was at 0.73 μN. Furthermore, the measurement range of the fabricated QCR force sensor probe was 0.73 μN through 50 mN.