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Abstract: In this paper, we present the concept of a microelectromechanical systems ring laser gyroscope (MEMS-RLG) and its optical components. MEMS-RLG has a semiconductor optical amplifier (SOA) enclosed with mirrors that form an optical loop for an external laser oscillator in free space. To confirm the feasibility of MEMS-RLGs, we constructed an experimental device with commercially available SOA and mirrors for external oscillation. We also show the fabrication and characteristics of optical components such as movable mirrors and a lens-positioning device, which are required for a miniaturized MEMS-RLG. [Copyright &y& Elsevier]

We present a novel method for 3D microfabrication with LIGA process that utilizes a deep X-ray mask in which a microactuator is integrated. The integrated microactuator oscillates the X-ray absorber, which is formed on the shuttle mass of the microactuator, during the X-ray exposures to modify the absorbed dose profile in X-ray resist, typically PMMA. The 3D PMMA microstructures according to the modulated dose contour are revealed after GG development. An X-ray mask with integrated comb drive actuator is fabricated using deep reactive ion etching, absorber electroplating, and bulk micromachining with silicon-on-insulator wafer. Silicon shuttle mass (1 mm×1 mm, 20 μm thick) as a mask blank is supported by four 1 mm long suspension beams and is driven by the comb electrodes. A 10 μm thick, 50 μm line and spaced gold absorber pattern is electroplated on the shuttle mass before the release step. The fundamental frequency and amplitude are around 3.6 kHz and 20 μm, respectively, for a dc bias of 100 V and an ac bias of 20 VP–P (peak–peak). Fabricated PMMA microstructure shows 15.4 μm deep, S-shaped cross-section in the case of 1.6 kJ cm−3 surface dose and GG development at 35 °C for 40 min. [Copyright &y& Elsevier]

[Display omitted] • Electromechanical model of both the comb drive and its suspension is introduced. • The current drive topology is presented, including extensive leakage compensation. • Different feedback sensor topologies are presented. • Extensive displacement error analysis is performed. • A 50 nm resolution over a 200 μ m displacement is achieved. We present the design of a novel driver for a comb drive actuator. This actuator is required to have both a large displacement of 200 μ m and a high resolution of 50 nm. Traditionally, electromechanical MEMS actuation is done under voltage control. In this paper, we want to examine a charge controlled driver, as it might provide some advantages. A comb drive under charge control exhibits a longitudinal displacement proportional to Q 2 / 3 , rather than V 2 in case of voltage control. This more linear behavior might help to increase the achievable displacement resolution. It can also be shown that the stability range of an actuator under voltage control, for any type of actuator, will never be larger than the range of that same actuator under charge control. However, for a well-designed and well-fabricated comb drive actuator, where this instability is expressed in lateral pull-in, this effect is minimal. In this paper, we first create an electromechanical model of a comb drive, to be used in simulation of our driver. The created model is based on a previously designed comb drive with a displacement of 200 μ m at 91.6 V, or 138.1 pC. We then focus on the driver itself, minimizing the effects of leakage currents, as these are detrimental for a good charge controlled actuation. As the actuator will be driven dynamically, we cannot rely on the estimated charge on the comb drive to determine the immediate displacement. A sensor is needed that measures the position of the comb drive. Four different topologies of sensors are described, each of which uses the comb drive itself to estimate its position. A full electromechanical simulation is performed and a comparison is made between the different sensor topologies, evaluating their ability to determine the exact displacement. One of the proposed sensor topologies achieved the 50 nm resolution. [ABSTRACT FROM AUTHOR]