Flexure hinges or material hinges are commonly used in mechanisms where accurate, and backlash free behavior is wanted. Because of limitations of the flexure hinge it is usually used for small angles. The maximum allowed angle is determined by the material properties. If larger angles are needed there are alternatives like a cartwheel hinge.
The flexure hing is made out of one piece of material. The movement of it is possible by deforming the material. In most of the designs this deformation is limited to the elastic region of the material. In designs where movement is limited to a low number of repetitions the movement may deform the material permanently due to high tension.
One of the great advantages of a material hinge is the lack of friction or backlash. Because there is no friction, there also is no hysteresis in the behavior. This and the lack of backlash make it ideal for use in mechanical designs that need high repetition accuracy.
This flexure hinge calculator makes it easy to calculate behavior of specific flexure hinge designs.