Browsing by Author "Fang, Weileun"

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A GENERALIZED FOUNDRY CMOS PLATFORM FOR CAPACITIVELY-TRANSDUCED RESONATORS MONOLITHICALLY INTEGRATED WITH AMPLIFIERS
(2010)
Chen, Wen-Chien
;
Chen, Che-Sheng
;
Wen, Kuei-Ann
;
Fan, Long-Sheng
;
Fang, Weileun
A generalized foundry CMOS-MEMS platform suited for integrated micromechanical resonator circuits have been developed for commercial multi-user purpose and demonstrated with a fast turnaround time and a variety of design flexibilities for resonator applications. With this platform, different configurations of capacitively-transduced resonators monolithically integrated with their associated amplifier circuits, spanning frequencies from 500kHz to 14.5MHz, have been realized with resonator Q\'s around 2,000. This platform specifically featured with various configurations of structural materials, different arrangements of mechanical boundary conditions, large transduction area, well-defined anchors, and performance enhancement scaling with IC fabrication technology, offers a variety of flexible design options suited for sensor and RF applications.
A photovoltaic pn junction micro vertical comb-drive actuator
(2010-10-01)
Huang, Hsin-Yu
;
Hsu, Hsiu-Ting
;
Lin, Hung-Yi
;
Chiu, Yi
;
Fang, Weileun
This study reports a novel micro electrostatic vertical comb-drive actuator (VCA) driven by the photovoltaic effect that results from incident light. The vertical comb electrodes have a pn junction structure (named pn-combs). The VCA with pn-combs can be driven by the photovoltaic effect. The combination of the photovoltaic effect and reverse bias can further increase the driving amplitude of the VCA. To demonstrate the feasibility of the proposed concept, the VCA with pn-combs was fabricated on an epitaxial silicon wafer (epi-wafer) and successfully driven resonantly by intensity-modulated laser light. The first torsional mode of a typical fabricated VCA is at 1.46 kHz. Moreover, VCA driven using (1) optical driving, and (2) optical driving with dc reverse bias, were also demonstrated. The angular displacement of the VCA was +/- 3.8 m deg by optical driving. The angular displacement of the VCA significantly increased to +/- 41 m deg after applying an additional dc reverse bias of 5 V.
Design and Fabrication of a Small-Form-Factor Optical Pickup Head
(2009-05-01)
Chiu, Yi
;
Shih, Hsi-Fu
;
Chiou, Jin-Chern
;
Cheng, Shih-Tung
;
Hung, Kuo-Yung
This paper presents the design and fabrication of a small-form-factor optical pickup head (OPH) for both red and blue wavelength. A holographic optical element (HOE) is used for beam splitting, aberration correction, and servo-signal generation to reduce the number of components and simplify the assembly procedure. In addition to demonstrating this OPH by using existing discrete components, several key components and processes are developed to use micro-electro-mechanical system (MEMS) technology to facilitate batch fabrication and wafer level assembly of the micro OPU.
Design, fabrication, and control of components in MEMS-based optical pickups
(2007-02-01)
Chiu, Yi
;
Chiou, Jin-Chern
;
Fang, Weileun
;
Lin, Yung-Jiun
;
Wu, Mingching
Small-form-factor optical pickups and disk drives have been an area of intense research since the rise of portable consumer electronic products. In current technology, most of the devices are manufactured by the precision assembly of discrete miniaturized optomechanical components. The assembly process can be simplified and cost reduced by using the batch fabrication processes developed in microelectro-mechanical systems (MEMS). In this paper, the fabrication and testing of optical and actuator components for a MEMS-based optical pickup are presented. A novel design methodology is also applied to the servo control system of the pickup.
Liquid crystal alignment in nanoporous anodic aluminum oxide layer for LCD panel applications
(2010-07-16)
Hong, Chitsung
;
Tang, Tsung-Ta
;
Hung, Chi-Yu
;
Pan, Ru-Pin
;
Fang, Weileun
This paper reports the implementation and integration of a self-assembled nanoporous anodic aluminum oxide (np-AAO) film and liquid crystal (LC) on an ITO-glass substrate for liquid crystal display (LCD) panel applications. An np-AAO layer with a nanopore array acts as the vertical alignment layer to easily and uniformly align the LC molecules. Moreover, the np-AAO nanoalignment layer provides outstanding material properties, such as being inorganic with good transmittance, and colorless on ITO-glass substrates. In this application, an LCD panel, with the LC on the np-AAO nanoalignment layer, is successfully implemented on an ITO-glass substrate, and its performance is demonstrated. The measurements show that the LCD panel, consisting of an ITO-glass substrate and an np-AAO layer, has a transmittance of 60-80%. In addition, the LCD panel switches from a black state to a bright state at 3 V(rms), with a response time of 62.5 ms. In summary, this paper demonstrates the alignment of LC on an np-AAO layer for LCD applications.
Vertical Alignment of Liquid Crystal on ITO Glass with Anodic Aluminum Oxide Thin Film
(2011)
Tang, Tsung-Ta
;
Hung, Chi-Yuan
;
Pan, Ru-Pin
;
Hong, Chitsung
;
Fang, Weileun
Anodic Aluminum Oxide (AAO) thin films have been demonstrated as a vertical alignment layer for nematic liquid crystal in recent years. To control the liquid crystal orientation by applying the electric field, the AAO alignment layers need to be fabricated on the transparent electrode. In this work, the liquid crystal cell with the AAO alignment layer on Indium Tin Oxide (ITO) transparent electrode has been demonstrated. The performance of the cell has been studied. The transmittance of AAO-ITO substrate is around 55%. The polar anchoring strength of the AAO-ITO cell with good vertical alignment is 1.32 center dot 10-4J/m2, and the response time is around 90ms.
Wafer Level Batch Fabrication and Assembly of Small Form Factor Optical Pickup Head
(2008)
Hsiao, Sheng-Yi
;
Lee, Chih-Chun
;
Chiu, Yi
;
Shih, Hsi-Fu
;
Chiou, Jin-Chem
A MEMS batch assembly process for fabricating small form factor optical pickup head is proposed to minimize the complexity of assembly. Electrical and optical components are sealed in a chamber. A silicon optical bench with a packaged laser diode and crystalline-plane mirrors is demonstrated.