Design of a tilt stage with low axis drift differentially driven by positive-negative Poisson’s ratio structures

In this study, a compliant tilt stage with low axis drift driven by the opposite contractive–expansive deformation structures is proposed. The stage incorporates a differential actuation unit consisting of an outer hexagonal positive Poisson’s ratio structure (PPRS) and an inner hexagonal negative Poisson’s ratio structure (NPRS), enabling tilting motion is achieved using only a single actuator and one pair of driving structures. Opposite yet identical deformations of the PPRS and NPRS are utilized to counteract parasitic displacement, thereby achieving low axis drift. A fixed rotational axis is further introduced to enhance motion stability. A static model of the mechanism is established, and its performance is validated through finite element analysis and experimental testing. The experimental results show that the ratio of axis drift to tilt angle is below 0.091 µm/mrad. The proposed design exhibits superior dynamic response and motion accuracy compared with conventional compliant structures.