this article studied static deflection, natural frequency and nonlinear vibration of a clamped-clamped microbeam under discontinues electrostatic actuation. the electrostatic actuation was induced by applying ac-dc voltage between the microbeam and electrode plate. in contrast to previous works, it was assumed that length of the electrode plate was smaller than that of the microbeam. in additio...

when power systems are expanded and connected together with weak tie lines, the low-frequency oscillations are increased and the stability margin of the power system decreases. therefore, when designing the transmission system to be used, it is necessary to maintain the dynamic stability of the power system, and to make sure to have the most possible stability margin. sssc is a facts device con...

A Grating Light Modulator (GLM) based on Micro-Electro-Mechanical Systems (MEMS) is applied in projection display. The operating principle of the GLM is introduced in this paper. The electromechanical characteristic of the passive matrix addressing GLM is studied. It was found that if the spring constant is larger, both the response frequency and the driving voltage are larger. Theoretical anal...

The increasing popularity of DVFS (dynamic voltage frequency scaling) schemes for portable low power applications demands highly efficient on-chip DC-DC converters. The primary aim of this work is to enable increased efficiency of on-chip DC-DC conversion for near-threshold operation of multicore chips. The idea is to supply nominal (high) off-chip voltage to the cores which are then “voltage-s...

The shuffle motor is a electrostatic stepper motor that employs a mechanical transformation to obtain high forces and small steps. A model has been made to calculate the driving voltage, step size and maximum load to pull as well as the optimal geometry. Tests results are an effective step size of about 85 nm and a maximum produced force of about 40 pN at 40V clamping voltage and 25 V actuator ...

this paper presents a new centralized adaptive method under frequency load shedding. sometimes, after initial frequency drop following severe disturbances, although the system frequency returns to its permissible value, however, the system might become unstable due to voltage problems. in this regard, the paper proposes a new centralized adaptive load shedding method to enhance the voltage stab...

this paper presents a comprehensive case study on electro-mechanical analysis of mems[1] variable capacitors. using the fundamental mechanical and electrical equations, static and dynamic behaviors of the device are studied. the analysis is done for three different modes, namely: dc (static mode), small signal ac and large signal regime. a complete set of equations defining dynamic behavior of ...

This paper deals with the effect of the intrinsic material length-scale parameter on the stability and natural frequency of a rectangular micro-plate for two different cases; fully clamped and fully simply supported. A variational formulation based on Hamilton’s principle and the modified couple stress theory is used to obtain the nonlinear governing equation of a micro-plate incorporating the ...

This paper reports the design, fabrication, packaging, and testing of a relay-type threshold accelerometer array. The array includes 15 different sense elements ranging from 10 to 150 g in 10 g increments, and triply redundant 20 and 100 g sense elements for a total of 19 elements. The devices were fabricated using a modified sacrificial LIGA technique that creates a 100–300 m thick nickel stru...

Neuromuscular assessment of rock climbers has been mainly focused on forearm muscles in the literature. We aimed to extend the body of knowledge investigating on two other upper limb muscles during sport-specific activities in nine male rock climbers. We assessed neuromuscular manifestations of fatigue recording surface electromyographic signals from brachioradialis and teres major muscles, usi...