Adaptive optical lenses based on the electrowetting principle are being rapidly implemented in many applications, such as microscopy, remote sensing, displays, and optical communication. To characterize the response of these electrowetting lenses, the dependence upon direct current (DC) driving voltage functions was investigated in a low-viscosity liquid system. Cylindrical lenses with inner di...

We present a new tri-electrode topology for reducing the control voltage for electrostatic actuators. Conventional parallel plate actuators are dual-electrode systems, formed by the MEMS structure and the drive electrode. By placing a perforated intermediate electrode between these elements, a tri-electrode configuration is formed. This topology enables a low voltage on the intermediate electro...

The present work addresses the control of torsional micro-mirrors assisted by a constant bias voltage. It is shown that such a configuration will have an effect of torque multiplication and hence, it will reduce the dynamic range of actuation signal. A nonlinear controller using backstepping and barrier functions is developed, which can guarantee closed-loop stability in a restricted range cove...

A novel vertical translational microactuator based on thin-film piezoelectric actuation is presented, using a set of four compound bend-up/bend-down unimorphs to produce translational motion of a moving platform or stage. The actuation material is a chemical-solution deposited lead-zirconate-titanate (PZT) thin film. Prototype designs have shown as much as 120 μm of static displacement, with 80...

We evaluate two novel reciprocal self-sensing methods for tapping-mode atomic force microscopy (TM-AFM) utilizing charge measurement and charge actuation, respectively. A microcantilever, which can be batch fabricated through a standard microelectromechanical system (MEMS) process, is coated with a single piezoelectric layer and simultaneously used for actuation and deflection sensing. The setu...

This paper reports on the design, fabrication, and testing of a low-actuation voltage Microelectromechanical systems (MEMS) switch for high-frequency applications. The mechanical design of low spring-constant folded-suspension beams is presented first, and switches using these beams are demonstrated with measured actuation voltages of as low as 6 V. Furthermore, common nonidealities such as res...

Electrostatic actuation of motion is commonly used in resonant MEMS. Drive signal feed-through is undesirable as it masks the detection signal. This paper reports analysis and demonstration of a resonant motion excitation scheme, which uses a combination of a DC bias with a sinusoidal AC voltage, frequency of which is twice of the mechanical resonant frequency. This configuration is experimenta...

A resonant absorption cavity that couples long-wavelength infrared (LWIR) light into a movable plate has been demonstrated for thermal detectors, especially microbolometers. Each device is continuously tunable over 8.7-11.1 microm by using electrostatic actuation with voltages from 0 to 42 V. The width of the resonance is relatively broad, approximately 1.5 microm, to match the large widths of ...

The static shape of droplets under electrowetting actuation is well understood. The steady-state shape of the droplet is obtained on the basis of the balance of surface tension and electrowetting forces, and the change in the apparent contact angle is well characterized by the Young-Lippmann equation. However, the transient droplet shape behavior when a voltage is suddenly applied across a drop...

− A new type of RF MEMS switch for low voltage actuation, high broadband application and high power capability is presented. Mechanical and electromagnetic simulations of this new RF MEMS switch type are shown and the fabrication process and measurement results are given. The switching element consists of a cantilever which is fixed by a suspension spring to the ground of the coplanar line. The...