Patent ID: 7855491

Claim:
A prestress-adjustable piezoelectric gripping device, comprising: a base, having a surface; a first sliding structure, disposed above the surface and substantially parallel to the surface; a gripping unit, having a first gripping element and a second gripping element, wherein the first gripping element has a first rod portion and a first gripping portion, the first sliding structure is used for guiding the first rod portion, and the second gripping element is disposed above the surface and is configured opposite the first gripping element; a piezoelectric unit, having at least one piezoelectric element and at least one substrate, wherein the piezoelectric element has a first side surface, a second side surface, and two electrodes, the first side surface is disposed on a side surface of the substrate, the second side surface is perpendicular to an axial extension direction of the first rod portion, and the electrodes are disposed on the first and second side surfaces respectively; a force-sensing unit, disposed on the other side surface of the substrate; and a prestressing device, connected to the force-sensing unit, for providing a prestressing force so that the piezoelectric element contacts the first rod portion.