This paper presents a large displacement static-electricity curled-hinge comb micro-mirror made by a CMOS-MEMS process. A micro-spring is incorporated to reduce the stress effects and the process variation. A mirror with a size of 500um x 500um is made using three metal layers. The micro-spring made a metal layer and a poly layer with a size of 4um x 21um. The nature frequency is 727 Hz and the maximum displacement of the micro-mirror is 32um using a driving voltage of 25 volts. The process variation has been successfully reduced from 30% to 10%.
The proposed pulse height analysis technique is based on the constant and linear relationship between pulse width and pulse height generated from front-end electronics of nuclear spectroscopic and imaging systems. The present technique has successfully implemented into the sump water radiation monitoring system in a nuclear power plant. The radiation monitoring system uses a NaI(Tl) scintillator to detect radioactive nuclides of Radon daughters brought down by rain. The technique is also used for a nuclear medical imaging system. The system uses a position sensitive photomultiplier tube coupled with a scintillator. The proposed techniques has greatly simplified the electronic design and made the system a feasible one for potable applications.
This paper presents a ball type microlens made of photoresist SU-8, which allows light focusing in all directions on the substrate surface and thus provides application flexibility. We have developed a low temperature batch process that uses UV lithography for patterning, bulk machining for nozzle fabrication, and then pressing SU-8 through nozzles for ball formulation. A 24 x 24 lens array has been fabricated. The micro-balls can be made with diameters from 80 to 500 μm and focal lengths from 50 to 300 μm. Measurements indicated that the error of the diameter was within 3%; variations among batches are within 10%. The major contribution to the uncertainty is due to the uncertainty of the pressing force. Spectral density distribution measurements were also performed to verify the focusing ability of ball lenses. The measured numerical aperture is about 0.63 that is satisfactory for most micro-optical applications.
A novel concept of perpendicular magnetic anisotropy is applied to electromagnetic micro-optical switch (EMOS). In the study, Fe/Pt equiatomic alloy thin film is potential high-density recording media and high-energy permanent magnetic because of their exceptional magnetic properties. EMOS combines of new type Fe/Pt alloy thin film, innovative design of closed magnetic circuit and single layer planar coil. The Fe/Pt alloy thin film and magnetic circuit with close loop is applied to concentrate the magnetic flux, increase magnetic force, and decrease switching time. In this EMOS, some important features are summarized as follows: (1) high magnetic force (>68mN); (2) low work voltage (<5V); and (3) short switching time (<0.4ms). The work demonstrates that EMOS can provide excellent performance than conventional magnetic microactuator.
The paper presents novel concepts of batch fabrication of micro-ball lens array technology integrated on the silicon based wafer by low temperature wafer bonding by which can improve appropriate distance of optical fiber coupling. The silicon based coupling platform consists of the self-parking framework, micro-ball lens array, and precision platform for optical fiber coupling purpose. The structure of optical platform is able to improve distance of between fiber and micro-ball lens and increase coupling efficiency. The micro- ball lens array is batch fabricated by polymeric material and melting photoresist through low temperature wafer bonding. Then batch assembly onto each other flat-topped mesa that adjoins to the v-groove. The corner compensation offers a method to fabricate self-parking framework and flat-topped mesa in the intersection of two v-grooves. This fabrication process not only provides accurate coupling distance between fibers and micro-ball lens but also reduces micro-assembly cost.
This paper presents a novel approach for bonding technique based on the concept of patternable and low temperature process. This method especially is suitable for the design of microstructure by surface micromachining. By this way, the bonding can be solved. The patternable intermediate of photoresist is applied to conduct wafer-bonding experiment. SU-8 is selected as intermediate layer the thickness of SU-8 not only can be easily controlled, but also can be patterned into any-shape by the technique. Furthermore, this method provides smooth intermediate pad to contact for bonding. The experiment of wafer-to-wafer intermediate bonding was conducted. The preliminary results show that the influences of high temperature, electric field, and void can be avoided. The tensile stress test is shown the bonding strength up to 216 kg/cm<SUP>2</SUP> can be reached.
The paper presents an innovative concept of self-parking ideal in v-groove and self-latching vertical mirror on the suspension diaphragm with technique out of plane fiber-optical switch arrays was fabricated. The self-parking ideal offers an integration by which the distance between optical fiber and mirror can be minimizes. The self-latching vertical mirror located on the suspension diaphragm that is supported by four cantilever beams. At first, it is achieved by bulk micromachining and is ablated by mask projection of 248 nm excimer laser. The vertical mirror structure was fabricated by thick photoresist as SU-8 through UV lithography and then sputters gold films. The fiber-optical switch solves in plane micro-optical that require large moving space, microassembly problem of fiber to mirror distance and reducing the roughness of mirror surface. In the experiment, out of plane micro-optical switch are successfully achieved by above key process. By the measurement of roughness of mirror must be less than 20 nm rms. The reflectivity of the gold films mirror by a wavelength of 1310 nm is higher than 85%. The micro-optical switch has maximum displacement 48 micrometers and switching time is below 0.4 ms with driving voltage 100 V DC.