This paper presents a novel piezoelectrically actuated dual-axis micro manipulator with an asymmetric compliant structure. The mechanical design of the micro manipulator is first presented. A novel guiding bridge (GB)-type mechanism was proposed and utilized in the left part of the micro manipulator to improve the dynamic performance of the micro manipulator. The analytical model has been established based on pseudo-rigid-body (PRB) model and matrix-based compliance modeling (MCM) method. The kinematic and the precision of the micro manipulator have been analyzed, and the input and output couplings have been investigated. The prototype of the micro manipulator has been fabricated by wire electro discharge machining (WEDM). Then, open-loop experimental tests have been performed. The experimental results match well with the analytical calculation, and the amplification ratios are 11.12 and 4.64 for the left part and right part, respectively. Proportional-integral (PI) controller has been used to regulate the output displacement and grasping force, and a series of closed-loop experiments have been conducted to investigate the performance of the micro manipulator. The results show that the position resolution for both the right and left parts is 0.15 μm, and the force resolution is 4 mN.

To realize high precision rotation angle adjustment in micro/nano manipulation, a novel monolithic 2- degree of freedom (DOF) pure rotation platform is designed, fabricated and tested in this paper. The rotation platform is driven by two piezoelectric (PZT) actuators. Rotation decoupling is realized based on three Hooke's joints and a large rotation range is obtained based on two bridge-type mechanisms. Compared with other rotation platforms, the developed 2-DOF pure rotation platform has the advantages of fewer actuators due to rotation decoupling design and larger working frequency range due to compact structure and monolithic fabrication. An analytical model is established to calculate transmission ratio and input stiffness. The dominant parameters are determined based on sensitivity analysis. Finite element analysis (FEA) is conducted to investigate the characteristics of the rotation platform. Experimental tests are carried out to investigate the performance of the rotation platform. Decoupling test results show the maximum rotation angles in X- and Y- axes are 2.04 mrad and 2.12 mrad, respectively, and the X- and Y- axes relative coupling errors are 2.03% and 2.09%, respectively. Closed loop control results show that the settling time is 40 ms and the resolutions in X- and Y- axes are both 5 μrad.

This paper presents an analytical model for soft pneumatic network actuators (PneuNets) consisting of a series of chambers made of elastomeric material and an inextensible bottom layer. The model links the input pressure with the bending angle in free space and the tip force of the PneuNets. The bending principle of the PneuNets is comprehensively analyzed through the analytical model. The bending angle of PneuNets is analyzed considering the deflection of the gap layer. The tip force of PneuNets is analyzed considering the equilibrium moment of the PneuNets at the applied pressure. This paper focuses on the deformation of the gap layer of the PneuNets and the effect of gap length on the bending angle. The proposed model considers the deformation of the lateral wall of the chamber as the deformation of the nonlinear hyperelastic membrane. Futhermore, the contact moment is included considering the Hertzian contact between the adjacent chambers. Finite element analysis and physical experiments are carried out and the results show that the bending angle and tip force of the PneuNets can be effectively predicted by the analytical model with an error of less than 10%.