超声集聚微纳米物质的压电器件结构设计和原理分析

发布时间：2018-06-03 00:11

本文选题：超声换能器 + 反节点　；参考：《南京航空航天大学》2014年硕士论文

【摘要】：压电换能器是一种依靠压电材料的正、逆压电效应来实现电能与机械能之间互相转换的器件。压电换能器为超声技术应用的主要工具，其种类多且用途非常广泛，，其中在微纳米物质操纵上的应用前景非常广阔。本课题研究均直型超声针换能器工作时利用声学流驱动微纳米物质在针身反节点或者整个针身下面的硅基板上集聚的特性，主要研究内容如下：介绍了操纵微纳米物质现有的各种方法及各自的优缺点，详细的介绍了超声操纵微纳米物质目前的研究现状、压电驱动技术，并且阐述了本研究课题的目的、范围以及课题意义。通过实验与理论相互验证的方法，研究了均直型超声针换能器驱动微纳米物质集聚的特性与机理。超声针在高频振动下集聚微纳米物质，其工作在弯曲模态。此时针身反节点两边会形成对称的声学流，从而驱动微纳米物质跟随声学流到针身反节点下基板上成线性非连续斑点集聚。研究了当在成斑点集聚的实验操作基础上再增加在针身轴向上的均匀往复运动，从而实现微纳米物质在整个针身下集聚成线连续集聚。研究了声学流产生的原因，并利用有限元软件COMSOL计算仿真了针身反节点周围的声学流图案，其与实验中观察得到的声学流图案是一致的。同时对靠近基板的声学流集聚微纳米物质作了力学分析，估算出基板上单个酵母菌所受驱动力的数量级为。
[Abstract]:Piezoelectric transducer is a kind of device which depends on the direct and inverse piezoelectric effect of piezoelectric material to realize the mutual conversion between electrical energy and mechanical energy. Piezoelectric transducer is the main tool for ultrasonic technology. It has a wide range of applications and has a broad application prospect in the manipulation of micro-nano materials. In this paper, we study the characteristics of micro and nano materials agglomerating on the antinode of the needle body or the silicon substrate under the needle body when the straight ultrasonic needle transducer works. The main research contents are as follows: This paper introduces the existing methods of manipulating micro and nano materials and their advantages and disadvantages, introduces in detail the current research situation of ultrasonic manipulation of micro and nano materials, piezoelectric driving technology, and describes the purpose of this research subject. Scope and significance of the project. By means of experimental and theoretical verification, the characteristics and mechanism of uniform straight ultrasonic needle transducer driving the aggregation of micro and nano materials are studied. The ultrasonic needle accumulates the micro-nano material under the high frequency vibration, and it works in the bending mode. At this time, symmetrical acoustic flow will be formed on both sides of the needle body anti-node, which drives the micro-nano matter to follow the acoustic flow to the substrate under the needle body anti-node to form linear discontinuous speckle aggregation. The uniform reciprocating motion in the axial direction of the needle body was studied on the basis of the experimental operation of speckle agglomeration, so as to realize the continuous aggregation of micro and nano materials under the whole needle body. The cause of acoustic flow is studied, and the acoustic flow pattern around the anti-node of needle body is simulated by the finite element software COMSOL, which is consistent with the acoustic flow pattern observed in the experiment. At the same time, the acoustic flow near the substrate was analyzed, and the order of magnitude of the driving force of the single yeast on the substrate was estimated.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB552

【共引文献】