Miniaturized Piezo Tube Actuators in Scanning Probe Microscopy

Scanning probe methods in microscopy allow topographic images with a resolution in the sub-nanometer range. In AFM (Atomic Force Microscopy), the scanning force microscope guides the measuring tip over the sample surface in a defined scanning pattern. Therefore, forces are measured between the very thin measuring tip and the object surface, providing information about the topography of the surface with a lateral resolution up to the picometer range. Other sample properties such as adhesion, stiffness, or viscosity can also be determined.

Miniaturized piezo tube actuators position AFM tip and sample

Miniaturized piezo tubes from PI Ceramic move the scanning element of the scanning force microscope, consisting of a spring (cantilever) and the tip of the AFM, on the XYZ plane. The use of these piezo tubes with an outer diameter of 0.45 to 1.5 millimeters enables a particularly compact design and replaces the classic construction of individual tripods for X, Y, and Z movement. The decisive advantage is the high dynamics of these piezo scanning tubes: Since their motion is based on solid-state effects, they achieve a position resolution down to a few picometers at response times of a few microseconds. The achievable displacements are in the range of several 10 micrometers, for larger ranges over several hundred micrometers, this task is performed by piezo scanning stages.

For dynamic investigations such as those performed in the noncontact mode of atomic force microscopy (nc-AFM), additional piezo disks or plates are attached to the cantilever in order to induce dynamic vibration in the measuring tip. The AFM tip remains a few ten nanometers above the surface, but does not touch it. This method can be used to generate pictures even of atomic structures.

Find out more about the possibilities of miniaturized piezo components here.