Design of two-dimensional piezoelectric laser scanner system for precision laser beam steering.

In this work, a large aperture two-dimensional (2D) piezoelectric laser scanner system with an onboard sensor to detect the scanner's deflection angle has been designed and prototyped. The proposed 2D laser scanner is driven using three amplified piezoelectric actuators assembled in an equilateral triangle configuration to provide structural stability and compactness. To overcome the nonlinearity that derives from the hysteresis effect of the piezoelectric actuators, the tip-tilt principle and the control schemes of the 2D scanner are analyzed and compared. Thanks to the combination of onboard sensing of the deflection angle of the scanner with the closed-loop control capability, this 2D scanner's features include a large aperture and high accuracy. The experimental results demonstrate that closed-loop control achieves higher control accuracy than the open-loop control approach, leading to a reduction in the relative error from 2%-4% to ∼0.5%, while the deflection angle tracking accuracy lies approximately within the 40 µrad range.

Investigation of a Liquid-Phase Electrode for Micro-Electro-Discharge Machining.

Micro-electro-discharge machining (µEDM) plays a significant role in miniaturization. Complex electrode manufacturing and a high wear ratio are bottlenecks for µEDM and seriously restrict the manufacturing of microcomponents. To solve the electrode problems in traditional EDM, a µEDM method using liquid metal as the machining electrode was developed. Briefly, a liquid-metal tip was suspended at the end of a capillary nozzle and used as the discharge electrode for sparking the workpiece and removing workpiece material. During discharge, the liquid electrode was continuously supplied to the nozzle to eliminate the effects of liquid consumption on the erosion process. The forming process of a liquid-metal electrode tip and the influence of an applied external pressure and electric field on the electrode shape were theoretically analyzed. The effects of external pressure and electric field on the material removal rate (MRR), liquid-metal consumption rate (LMCR), and groove width were experimentally analyzed. Simulation results showed that the external pressure and electric field had a large influence on the electrode shape. Experimental results showed that the geometry and shape of the liquid-metal electrode could be controlled and constrained; furthermore, liquid consumption could be well compensated, which was very suitable for µEDM.

[An Emerging Simulation Method Used in System Simulation of Flow Chamber of Hematology Analyzer].

In fluid flow field analysis, the common simulation method is 1-D simulation or 3-D simulation, In order to analyze blood fluid system more quickly and accurately and choose the appropriate sample tube at the beginning of design for the system, this paper adopts a recently emerging 1D-3D simulation method to make simulations of flow chamber subsystem. Respectively using Flow master and ANSYS system modeling, use MpCCI connects the two parameter coupling, realize the sheath fluid velocity of research. The software can meet the needs of design and analysis of the Hematology Analyzer fluid system. In this paper, the method of co-simulation for medical apparatus and instruments of Hematology Analyzer fluid system development provides a new method, has important significance on the subsequent simulation.