Takuya Imahashi

Preparation of Piezoelectric Thick Films using a Jet Printing System.

Pb(Zr, Ti)O3 piezoelectric thick films were prepared on Pt/Cr/SiO2/Si substrate using an improved jet printing system (JPS). X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis and measurements of electrical properties, including dielectricity, ferroelectricity and piezoelectricity, were carried out on these films. A very high deposition rate of 3 µm/min and films with thicknesses above 100 µm were obtained without peeling. However, the films prepared in this fashion demonstrate lower piezoelectric behavior than bulk PZT ceramics. The reason for this has been explored using element analysis. Furthermore, we have developed a mask depositing technique as a surface leveling.

Tactile sensor using piezoelectric resonator

A new type of tactile sensor probe head which detects compliance of live tissue has been developed. The sensor consists of a Colpitts circuit including a 1.5 mm/spl times/1.5 mm piezoelectric resonator on a mount 2.4 mm in diameter. This size is small enough to be inserted into the human body. Experimental results show that the oscillating frequency change versus the contact force is related to the object compliance. Especially, the maximum gradient of the oscillating frequency versus contact force curve is able to identify the difference of the compliance. It is possible to measure accurate compliance without setting the contact force constant.