Study Of Photothermal Microacuators Based On LIGA Technology

Micro/Nano technique and Micro-Opto-Electro-Mechanical System(MOEMS) represent the research tendency of future science and technology. Micro drive technique, as an important part of MOEMS, gets more and more attention of researchers all over the world. A new micro drive technique is introduced in this dissertation, which is called photo-thermal micro drive technique. Several kinds of metal photo-thermal micro drive structures are designed and manufactured by LIGA technique. Photo-thermal micro actuators have advantages of simple structure, a wide range of optional materials, easy manipulation, relatively large output force, non-contact control, high degree of miniaturization and integration. They are a kind of innovate micro actuator with comprehensive application prospect.The development of MOEMS, micro actuator and micro/nano manufacturing technique are first introduced at the beginning of this dissertation. Then the classic process, applications, and advantages of LIGA technique are described in detail. The LIGA station of Beijing Synchrotron Radiation Facility is also described in detail, including some selections of parameter for manufacturing metal micro actuators.The mechanism of thermal expansion is analyzed by both theoretical and simulative method. Simulations of micro expansion arm's thermal model are carried out using the finite element analysis software ANSYS. Simulations reveal the effect of thermal conductivity, laser power and laser spot's position on micro expansion arm's temperature and deformation.On the basis of theoretical and simulative research, several kinds of photo-thermal micro drive structures are designed. Some simulations of switch-type and V-type photo-thermal micro actuators are carried out. By LIGA technique, switch-type photo-thermal micro actuators, V-type photo-thermal micro actuators and other photo-thermal micro structures are manufactured using nickel. A control and microscopic observation system of photo-thermal micro drive structures is built, which includes Laser, light path of drive control, light path of microscopy imaging, CCD imaging module and software for measurement and analysis.A series of experiments are carried out on the photo-thermal micro drive structures, especially on the switch-type and V-type photo-thermal micro actuators, in order to reveal the effect of laser spot's position and laser power on micro actuator's deformation. Micro actuators' speed of response under Lasers of different frequency is also tested. Moreover, some exploratory researches for application are done on photo-thermal micro actuators.The achievements of this whole subject are concluded at the end of this dissertation. Meanwhile some insufficient points of our works are pointed out, and some directional advices on the future research are provided as well.