| 摘要 |
<p>[Problem] A center of a multi-layer piezoelectric element is an active region and deforms to a greater degree than ends thereof which is an inactive region during driving operation, and is therefore more susceptible to stress concentration and crack development. [Solution] A multi-layer piezoelectric element (1) includes a columnar stacked body (15) in which piezoelectric layers (11) and internal electrode layers (13) are alternately laminated, and a pair of external electrodes configured to bond to side faces of the columnar stacked body (15), wherein a side face of the columnar stacked body (15) is configured so that a surface roughness of a center of the side face in a stacked direction of the columnar stacked body (15) is greater than those of ends of the side face in the stacked direction of the columnar stacked body (15). This makes it possible to relax the stress exerted on the side face of the columnar stacked body (15), and thereby enhance the durability of the multi-layer piezoelectric element (1).</p> |
