Electrodeposition of Ni-Fe alloys, composites, and nano coatings–A review

A nonlinear strain gradient beam formulation

Size dependent buckling analysis of microbeams based on modified couple stress theory with high order theories and general boundary conditions

This work reports on piezoelectric aluminum nitride (AlN) based dual-beam RF MEMS switches that have been monolithically integrated with AlN contour-mode resonators. The dual-beam switch design presented in this paper intrinsically compensates for the residual stress in the deposited films, requires a low actuation voltage (5 to 20 V) and facilitates active pull-off to open the switch and exhibits fast switching times (1 to 2 µs). This work also presents the combined response (cascaded S parameters) of a resonator and a switch that were co-fabricated on the same substrate. The response shows that the resonator can be effectively turned on and off by the switch. A post-CMOS compatible process was used for the co-fabrication of both the switches and the resonators. The single-chip RF solution presented constitutes an unprecedented step forward towards the realization of compact, low-loss and integrated multi-frequency RF front-ends.

/pdf/dual-beam-actuation-of-piezoelectric-aln-rf-mems-switches-4wgij1572o.pdf

Dual-Beam Actuation of Piezoelectric AlN RF MEMS Switches Monolithically Integrated with AlN Contour-Mode Resonators

Analytical solutions for the size dependent buckling and postbuckling behavior of functionally graded micro-plates

A radio-frequency micro-electro-mechanical systems (RF MEMS) switch with bistable states based on electromagnetic actuation is presented The switch has two stable positions due to the adoption of the permanent magnets, which will lead to a lower power consumption of the device With electromagnetic actuation arising from the planar coils, the cantilever beam can switch from one stable position to the other The structure sizes of the switch are simulated by the finite element software of the ANSYS 70 The device with a size of 20 mm × 22 mm is fabricated by UV-LIGA technology A current pulse with an amplitude of 50 mA is needed for the fabricated switches’ switching between two stable states that is in good agreement with the simulation, and the switching time is only approximately 20 μs The insertion loss is −011 dB, and the isolation is −43 dB at 3 GHz

Preparing of a high speed bistable electromagnetic RF MEMS switch

Electroplating of low stress permalloy for MEMS

The residual stress in the electroplated magnetic films is an important factor that limits the functionality of many micromagnetic devices. We have investigated the stress in electroplated Ni-Fe alloy for MEMS as a function of bath concentration, utilizing the wafer-bending method. Our investigation demonstrated that a low-concentration plating solution decreases the residual stress in the electrodeposits, and the stress is further decreased by increasing the saccharin additive content. We obtained the low-stress Permalloy Ni/sub 81/Fe/sub 19/ in our experimental conditions. We fabricated a bistable electromagnetic RF MEMS switch with deformation-free cantilever beam using the electroplated Permalloy.

Low-stress permalloy for magnetic MEMS switches

A radio-frequency micro-electro-mechanical systems (RF MEMS) switch with two stable states based on electromagnetic actuation is presented. The switch has two stable positions due to the use of the permanent magnets, which will lead to a low power consumption of the device. The micromechanical structure of the switch is designed and analyzed by means of mechanics and electromagnetism. The results show that the 13-/spl mu/m displacement of the cantilever beam in the switch model with stiffening rib can be achieved with the force of 20/spl mu/N on the beam, and the natural frequency of the switch is about 5600Hz. Electromagnetic analysis reveals that the driving force of 20/spl mu/N can be obtained by magnetic interaction.

Yong-hua Zhang

Papers

Preparing of a high speed bistable electromagnetic RF MEMS switch

Electroplating of low stress permalloy for MEMS

Low-stress permalloy for magnetic MEMS switches

Design and analysis of the micromechanical structure for an electromagnetic bistable RF MEMS switch

A fast switching bistable electromagnetic microactuator fabricated by UV-LIGA technology