| Piezo Flexure Nanopositioners For applications where extremely straight motion in one or more axes is needed and only nanometer or microrad deviation from the ideal trajectory can be tolerated, flexures provide an excellent solution. A flexure is a frictionless, stic-tionless device based on the elastic deformation (flexing) of a solid material (e.g. steel). Sliding and rolling are entirely eliminated. In addition, flexure devices can be designed with high stiffness, high load capacity and do not wear. They are also less sensitive to shock and vibration than other guiding systems. They are also maintenance-free, can be fabricated from non-magnetic materials, require no lubricants or consumables and hence, unlike air cushion bearings, are suitable for vacuum operation. Parallelogram flexures exhibit excellent guidance characteristics. Depending on complexity and tolerances, they have straightness/flatness values in the nanometer range or better. Basic parallelogram flexures cause arcuate motion (travel in an arc) which introduces an out-of-plane error of about 0.1% of the travel range (see Fig. 48). The error can be estimated by the following equation: |