Here we disassemble the piezoelectric assembly of a scanning probe microscope. At its core is a white cylinder of the piezoelectric material. If you look closely, it has a granular texture that reflects the fact that it is actually made up of many small crystals.
Within each crystal, atoms can be arranged in sequences such as the "Z" shown here. The bonds are ionic: electrons are not shared equally by neighboring atoms. Instead, electrons are pulled from the red atoms towards the blue atoms. This leaves the red atoms with a net positive charge, and the blue atoms with a negative charge.
