Monolithic parallel linear compliant mechanism for two axes ultraprecision linear motion

In this study, a new parallel linear compliant mechanism is presented for two axes ultraprecision linear motion. The compliant mechanism for ultraprecision motion is chiefly implemented by monolithically machined flexures. Therefore, considerable interest has focused on a compliant mechanism structure based on flexures. The design of a parallel linear compliant mechanism for two linear motions based on flexures requires that the compliant mechanism has a structure to reduce rotational parasitic motion. In addition, the flexures should be deformed by the bending moment rather than axial force. In order to satisfy these requirements, a compliant mechanism consisting of quad-symmetric simple parallel linear springs and quad-symmetric double compound linear springs is proposed. The compliant mechanism is designed using a mathematical model and analyzed by the finite element method. The compliant mechanism is integrated with piezoelectric elements for driving forces and capacitance-type displacement sensors into an ultraprecision stage for two linear motions. Experiments demonstrate the performance of the ultraprecision stage implemented by the compliant mechanism.