HIGH ASPECT RATIO MICRO-MACHINING OF MAGNETIC MATERIALS AND MAGNETIC MICRO-PUMP FOR MEDICAL USE

本研究的目的是开发可应用于MEMS（微电子机械系统）制造磁性微泵的基础技术，通过无导线磁场产生的空间能量驱动磁性微机器是可能的。这种无线驱动的特点使得磁性微机械在移动结构附近不需要驱动线圈，结构简单。另一方面，人体对传统线圈产生的磁场没有反应，因为水的渗透性非常小（抗磁性）。因此，将磁性微机械留在人体内，通过外加磁场从外部驱动它成为可能。这种医疗应用的微型机械只能通过磁驱动来操作。为了实现这种磁性微型机器，我们努力开发了以下基本技术。1)永磁体的微加工：采用模射法制备薄膜磁体，采用高纵横比Si和A12O3进行微加工。通过构建低温工作的电感耦合RIE机床，开发了纵横比在10左右的微加工技术。2)高能产品的薄膜磁体：为了用于模射法的薄膜磁体，努力开发快速淬火和电沉积的各向异性永久磁体。通过控制淬火速度和残余应力，制备了各向异性带状磁体和电沉积磁体。3)泵送压力高的微泵机构：为了泵送人体内的粘性液体，需要高的泵送压力机构和简单的结构。为达到上述目的，研制了几种放大泵模型，并进行了无线驾驶测试。

The aim of this research is to develop fundamental technologies which can be apply to fabricate magnetic micropump by MEMS(micro electro mechanical system)It is possible to drive the magnetic micro-machine through energy in space generated by magnetic fields without wires. This characteristic feature of the wireless driving make the magnetic micro-machine simple in structure because of lack of driving coils near moving structure. On the other hand, a human body does not respond to an applied field generated by conventional coils, since water has very small permeability(diamagnetism). So, it become possible to leave the magnetic micro-machine in a human body and drive it from outside by applied fields. Such medical application of micro-machine can be operated only by the magnetic driving. To achieve such magnetic micro-machine, effort was made to develop fundamental technologies listed below.1) Micro-machining of permanent magnets: To fabricate thin film magnets by mold-ejection method, micro-machining with high aspect ration of Si and A12O3 was done. By constructing the inductive coupling RIE machine operative at low temperature, micro-machining technology with aspect ratio around a few ten was developed.2)Thin film magnets with high energy products: To use for thin film magnets with mold-ejection method, efforts were made to develop anisotropic permanents magnets with rapid quenching and electro deposition. By control of quenching speed and residual stress, anisotropic ribbon magnets and electro -deposited magnets were developed.3) Micro-pump mechanism with high pumping pressure: For pumping sticky liquid in a human body, high pumping-pressure mechanism as well as simple structure are needed for the micro-pump. To achieve above purpose, several enlarged pump models were developed and tested by wireless driving.