Development of Microactuators Using Temperature Dependence of Surface Tension

利用表面张力的温度依赖性开发微执行器

基本信息

批准号：
11555058
负责人：
YOSHIDA Hideo
金额：
$ 8.77万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11555058/
关键词：
micro actuator surface tension Marangoni effect micropump

项目摘要

As is widely known, in the dimensions of micro electro mechanical systems (MEMS), surface forces are much more prevalent than body forces. This is because the former are proportional to the square power of length scales, while the latter are proportional to the cubic power.Therefore, we propose a new type of micropump system driven by surface tension, namely, the Marangoni effect using thermoelectric elements as temperature controllers. We distribute thermoelectric elements inside a channel, and trap an appropriate amount of gas between the elements ; the gas-liquid interfaces formed between the elements are the source of the pumping power. Each thermoelectric element has two junctions which absorb and discharge heat according to the Peltier effect. Since heat transfer from these junctions to the working liquid imposes temperature gradients along the gas-liquid interfaces, the flow from the hot-liquid side to the cold-liquid one is induced by the Marangoni effect. In order to boost the flow, many thermoelectric elements are distributed along the flow circuit. The features of this system are as follows : - The system does not contain any movable parts, and has a very simple structure. - There is no flow pulsation unlike the positive displacement pump. - There is no limitation on the electrical conductivity of the working liquid as encountered in EHD pumps. - Flow is easily controlled by the electric voltage applied to the thermoelectric elements. As a basic study of the present micropump system, a numerical simulation was made for twodimensional temperature and flow fields taking the electrical characteristics of the thermoelectric elements into account. Also, we tried to manufacture several micropumps, but operations were not successful because the deformation of gas-liquid interface induced unexpected eddies driven by free convection. However, a further trial based on micro fabrication techniques is currently in progress.

众所周知，在微电动机械系统（MEM）的尺寸中，表面力比体力更为普遍。这是因为前者与长度尺度的平方幂成正比，而后者与立方功率成正比。因此，我们提出了一种由表面张力驱动的新型微型泵系统，即，使用热电元素作为温度控制器，Marangoni效应使用Marangoni效应。我们在通道内部分布热电元件，并在元素之间捕获适当数量的气体；元素之间形成的气液接口是抽水功率的来源。每个热电元件都有两个连接，可根据Peltier效应吸收和排出热量。由于从这些连接到工作液体的热传递会沿气液接口施加温度梯度，因此从热液体侧到冷液体的流量是由Marangoni效应诱导的。为了提高流量，许多热电元件沿流动电路分布。该系统的功能如下： - 系统不包含任何可移动零件，并且具有非常简单的结构。 - 与正位移泵不同，没有流动脉冲。 - EHD泵中遇到的工作液体的电导率没有限制。 - 流动很容易由应用于热电元件的电压控制。作为当前微型泵系统的基本研究，对两性温度和流场进行了数值模拟，并考虑了热电元件的电气特性。另外，我们尝试制造几个微型聚集，但是操作并没有成功，因为气体液体界面引起的意外涡流的变形是由自由对流驱动的。但是，目前正在进行基于微制造技术的进一步试验。