A spatial 3-DOF piezoelectric robot and its speed-up trajectory based on improved stick-slip principle

Piezoelectric robots have been proven to be suitable for high-precision, cross-scale micro-nano manipulation due to their nanometre resolution and high flexibility. To make up for the limited stroke of micro-nano positioning platforms, a spatial three-degrees-of-freedom (3-DOF) piezoelectric robot is proposed in this study to enable three-dimensional micro-nano manipulation of objects. The robot utilizes the deformation of the piezoelectric stack as the source of displacement. It is comprised of a parallel compliant mechanism and a guided compliant mechanism in series, resulting in a compact robot body. The robot is capable of linear displacement in x -, y- and z -axes. The stiffness of the guided compliant mechanism is calculated using theoretical modeling and compared with the finite element simulation results, with a deviation of less than 5.6% verifying the accuracy of the model. The robot operates using two motion principles: the direct drive principle, which has a resolution of 16, 15, and 11 nm in x -, y- and z- axes, and a motion space of 13×11×7 μm 3 ; and the improved stick-slip principle, which has a theoretical infinite stroke and a maximum speed of 4.2 and 3.9 mm/s in x- and y- axes. The speed of the improved stick-slip principle is 42% higher than that of the traditional stick-slip principle in x- and y- axes. The robot has a spatial 3-DOF, nanometre resolution, millimeter speed, and can carry more than 500 g. • A piezoelectric robot is proposed to perform three-dimensional displacement. • The robot exhibits nanometer resolution and flexibility for precise operations. • The stick-slip principle has been improved to enhance the speed of the robot. • Cross-scale motion is achieved by direct drive and improved stick-slip principle.