光刻物镜中压电陶瓷驱动器的动态性能研究

针对压电陶瓷在光刻机投影物镜中作为像质补偿镜组促动器的特定应用要求,对一种以集成运算放大器构成的压电陶瓷驱动器的动态性能进行了研究.首先,针对驱动器系统中集成运放固有频率特性对动态性能的影响进行了分析,确定了外部补偿网络的参量.然后,针对驱动器系统大容性负载对动态性能的影响进行了分析,提出了隔离电阻的补偿方法.最后,讨论了驱动器系统中寄生电容对动态性能的影响.计算表明:补偿后的压电陶瓷驱动器系统相位裕量为79 °,阶跃响应无超调量,调节时间为5 μS.基本满足压电陶瓷在光刻物镜中作为像质补偿镜组促动器的稳定性强、响应快速、超调量小等动态要求.     

压电/纤维复合材料耦合旋转驱动器力学设计模型

本文在经典层合板理论和三维压电材料本构方程的基础上,依据压电材料与纤维复合材料之间的相互作用、位移连续条件,建立了压电—纤维复合材料旋转耦合驱动器力学模型,并推导出电耦合方程。计算和初步实验说明,这种新型结构的压电伸缩变形—离轴纤维复合层扭转变形耦合旋转驱动器比同类型驱动器能量密度高、转矩大,且这种旋转电机结构简单紧凑、工作稳定、寿命长、预计随着研究的进一步深入,可望成为一种新型的微致驱动器而广泛应用于微型机械、精密测量和自动控制等领域。     

PZT 95/5铁电陶瓷的冲击压缩Hugoniot特性研究

 采用一级气体炮加载装置,利用加窗VISAR技术,对极化和未极化两种状态的PZT 95/5铁电陶瓷进行了逆向冲击实验,在0.52~3.8 GPa冲击压力范围内,得到了PZT 95/5铁电陶瓷两种状态的σ-u关系。对比文献已有实验数据显示,PZT 95/5铁电陶瓷的Hugoniot曲线与初始密度值密切相关,高密度的PZT 95/5铁电陶瓷在0~3.0 GPa压力范围内的σ-u关系接近线弹性,较低压力下不同极化状态的Hugoniot数据表明,PZT 95/5铁电陶瓷发生了冲击相变。     

Adjustable low dynamic pumps based on hydrogels

This paper discusses the suitability of hydrogel actuators as drives of automatic pumps for long-term drug release. We demonstrate that such actuators can execute a defined task if several functional units are connected serially. Investigated functions of this pump are the adjustability of the time-delay from the initial operation up to the beginning of the drug release, opening the sterile drug ampoule, and the drug release at a specified timeframe. The described parameters to influence the pump behaviour are satisfying only for realization of continuous working devices. An outlook of the development of programmable pulsate pumps is given.     

Polymeric Macro-Molecular Piezoelectric Sensors for Evaluation of Structural Damage

Finding damages and their prevalence in structures is a very challenging problem. In order to identify potential structural damage, non-destructive methods are not very helpful. One of the most popular piezoelectric ceramic materials used worldwide is macromolecular lead zirconate titanate (PZT), also known as Pb[Zr(x)Ti(1-x)]O3. PZT transducers are proving to be a successful alternative for assessing the structure's health. The Macro-molecular PZT's self-actuating and sensing properties are utilized by the electromechanical impedance (EMI) method. In this capacity, the macro-molecular PZT patches serve as co-located actuators and sensors and make use of ultrasonic vibrations to produce a distinctive admittance “signature” of the structure. PZT patches perform exceptionally well in terms of damage sensitivity. The higher modes of vibration are locally activated by the local application of an AC source on the PZT transducers attached to the host structure. The alteration of the admittance response is a sign of injury to the transducer's vicinity. In the current study, the damage percentage and its location in a 150 × 150 × 150 mm concrete cube are being examined. Regression analysis is also used to determine the concrete cube's strength. This method also can identify hair-like cracks at an early stage, which explains how it can shield the building from serious failures.