We propose an approximate analytical solution to the pull-in voltage of a microcurled cantilever beam. The analytical model considers the realistic situations, which include stress gradient, nonideal boundary conditions, and fringing field capacitance. The proposed analytical model can be used at wafer level for extracting the Young's modulus of the thin film of which the cantilever beam is made. The approximate analytical solution is obtained based on the Euler's beam model and the minimum energy method. The accuracy of the proposed model is verified to be more accurate than the other published models. The model presented in this work can be used for wafer-level evaluation of the material properties through simple electrical testing and is also expected to find use in the design of microelectromechanical devices.
This research shows the realization of 2.4-GHz film bulk acoustic wave (FBAW) filters. The design, simulation, fabrication, measurement, and analysis of the film bulk acoustic wave resonator (FBAR) devices are covered, which is helpful for the manufacture of the FBAR devices. The simulation of the FBAR and RF circuitry can be integrated on a single platform. The fabrication of the FBAW filters is compatible with complementary metal-oxide semiconductors. This device can be used in 2.4-GHz bandpass filters, such as 802.11b/g and Bluetooth. In this research, the 2.4-GHz FBAW filters for wireless communication have been accomplished. The fabricated FBAW filters have insertion loss of −10 dB, return loss of −7 dB, and stopband rejection of −25 dB, central frequency of 2.485 GHz, bandwidth of 60 MHz, and size of 0.5 mm×0.5 mm.
This work presents the micro-machined 2-D switch array for use on free-space optical interconnect platform integrated with a digital 1x8 de-multiplexer control circuit together. Moreover, this device employs electrostatic actuation for light beam directions control. The CMOS-MEMS array-based optical platform contains 10x10 circular micromirrors switching spots, the diameter of each mirror is about 50 μm and the overall chip size is around 2 mm by 2 mm. The commercialized simulation softwares were used to validate the micromirror design and elucidate the behavior of the micromirror before fabrication. The post-process simply employs HF based solution to etch silicon dioxide layer to release the suspended mirror structures. The micromirror array is actuated using an electrostatic force. The results reveal that the micromirror has a tilting angle of around 8° according to the triangular relation with a driving voltage of 18V at pull down state. Also described herein are the general principles of the light-beam switching method used, the detailed of device design, the post-CMOS fabrication process flow, the result of simulations and preliminary experimental results are discussed.
This study presents a novel method based on the surface acoustic wave (SAW) sensor, for monitoring the thickness of a silicon membrane in real time during wet etching. Similar to accelerometers and pressure sensors, some micro-electro-mechanical systems (MEMS) devices require the thickness of silicon membranes to be known precisely. Precisely controlling the thickness of a silicon membrane during wet etching is important, because the thickness strongly affects post-processing and device performance. Moreover, the proposed surface acoustic wave sensor allows the thickness of a silicon membrane to be monitored from a few μm to hundreds of μm in situ, which depends on the periodicity of interdigital transducers (IDT). A novel method, which differs from any in previous work on etch-stop techniques, is developed in-situ for monitoring the thickness of a silicon membrane during wet etching. In summary, the proposed method for measuring the thickness of a silicon membrane in real time, is highly accurate; is simple to implement, and can be mass-produced. This work also describes the principles of the method used, detailed process flows, the method of taking measurements and the simulated and experimental results. The theoretical and measured values differ by an error of less than 2.50μm, so the results closely agree with each other.
This investigation fabricates a laminated-suspension microelectromechanical filter by a fully compatible CMOS process. Experimentally, due to the top metal layer begin used as the etch-resistant mask during the subsequent dry etching. Therefore, this study performs maskless etching with plasma and obtains excellent result including high selectivity and full release of the structure. Additionally, the MEMS filter can be driven by applying low-voltage of around 5 volts and a measured center frequency of around 13.1kHz and a quality factor of around 1871 were obtained for a single-comb resonator operate din air. The filter proposed herein has a monolithic integration capability with the relative electric circuits.
A microcomputer-controlled pulse laser holographic system is constructed by using a high performance hardware and a software based on a graphical language. The development of the hardwares and the intelligent man-machine interface software is described. Complexity of the hardwares for studying dynamic events is reduced. Tests and simulations of this system on a vibrating blade demonstrated its usefulness. The system is relatively simple, easy to control for various applications.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.