A Compliant MEMS Device for Out-of-Plane Displacements With Thermo-Electric Actuation

2014 ◽  
Vol 23 (3) ◽  
pp. 661-671 ◽  
Author(s):  
Giuseppe Vitellaro ◽  
Gaetano L'Episcopo ◽  
Carlo Trigona ◽  
Bruno Ando ◽  
Salvatore Baglio
Keyword(s):  
Thermo Electric ◽  
Out Of Plane ◽  
Mems Device ◽  
Electric Actuation

Structural Behavior of Microbeams Actuated by Out-of-Plane Electrostatic Fringing-Fields

2013 ◽  
Author(s):  
Hassen M. Ouakad
Keyword(s):  
Electrostatic Force ◽  
Order Model ◽  
Electrostatic Problem ◽  
Reduced Order ◽  
Gate Electrodes ◽  
Out Of Plane ◽  
Base Functions ◽  
Mems Device ◽  
System Frequency ◽  
Fringing Fields

In this paper, we present an investigation of the static behavior of a doubly-clamped microbeam actuated electrically through out-of-plane electrostatic fringing-fields. The distributed electrostatic force is caused by the asymmetry of the fringing-fields. This is actually due to the out-of-plane asymmetry of the beam and its two actuating stationary electrodes. The electric force was approximated by means of fitting the results of two-dimensional numerical solution of the electrostatic problem using Finite-Element Method (FEM). Then, a reduced-order model (ROM) was built using the Galerkin decomposition with linear undamped modes of a clamped-clamped beam as base functions. The ROM equations are solved numerically to get the static response of the considered micro-actuator when actuated by a DC load. Results shows possibility of having three different regimes for this particular MEMS device: a bending regime, a catenary regime, and an elastic regime. Eigenvalue problem is then solved to get the variation of the fundamental natural frequency when the system is deflected by a DC load. Results show that controlling the microbeam stroke, with a DC voltage on the gate electrodes, enables us to tune the system frequency, resulting in a possibility of a tunable MEMS device without a pull-in scenario.

scholarly journals Compliant MEMS Motion Characterization by Nanoindentation

2007 ◽  
Vol 1052 ◽  
Author(s):  
Joseph Choueifati ◽  
Craig Lusk ◽  
Xialou Pang ◽  
Alex A. Volinsky
Keyword(s):  
Mechanical Response ◽  
Compliant Mechanisms ◽  
Lateral Force ◽  
Macroscopic Modeling ◽  
Out Of Plane ◽  
Mems Device ◽  
Motion Characterization ◽  
Force Displacement

AbstractLarge out-of-plane displacements can be achieved when compliant mechanisms are utilized in MEMS. While mathematical and macroscopic modeling is helpful in building original designs, the actual MEMS device motion needs to be characterized in terms of the forces and displacements. A nanoindentation apparatus equipped with Berkovich diamond tip was used in an attempt to actuate and characterize the motion of the Bistable Spherical Compliant Micromechanism with a nonlinear (approximately cubic) mechanical response. Based on the obtained lateral force-displacement data it was concluded that the Berkovich diamond tip was too sharp, thus cutting through the polysilicon material of the MEMS device.

Grain separation enhanced magnetic coercivity in Pt/Co multilayers.

1993 ◽  
Vol 51 ◽  
pp. 1038-1039 ◽  
Author(s):  
G.A. Bertero ◽  
R. Sinclair
Keyword(s):  
Remanent Magnetization ◽  
Strong Influence ◽  
Uniaxial Anisotropy ◽  
Magnetic Coupling ◽  
Recording Media ◽  
Magnetic Media ◽  
Signal To Noise ◽  
Out Of Plane ◽  
Longitudinal Recording ◽  
The Relationship

Pt/Co multilayers displaying perpendicular (out-of-plane) magnetic anisotropy and 100% perpendicular remanent magnetization are strong candidates as magnetic media for the next generation of magneto-optic recording devices. The magnetic coercivity, Hc, and uniaxial anisotropy energy, Ku, are two important materials parameters, among others, in the quest to achieving higher recording densities with acceptable signal to noise ratios (SNR). The relationship between Ku and Hc in these films is not a simple one since features such as grain boundaries, for example, can have a strong influence on Hc but affect Ku only in a secondary manner. In this regard grain boundary separation provides a way to minimize the grain-to-grain magnetic coupling which is known to result in larger coercivities and improved SNR as has been discussed extensively in the literature for conventional longitudinal recording media.We present here results from the deposition of two Pt/Co/Tb multilayers (A and B) which show significant differences in their coercive fields.

Anisotropy of Nanoindentation – a tool for the determination of nanocrystal orientation ?

2003 ◽  
Vol 779 ◽  
Author(s):  
David Christopher ◽  
Steven Kenny ◽  
Roger Smith ◽  
Asta Richter ◽  
Bodo Wolf ◽  
...  
Keyword(s):  
Crystal Surface ◽  
Scanning Force Microscopy ◽  
Depth Range ◽  
Dislocation Loops ◽  
Force Microscopy ◽  
Pile Up ◽  
Out Of Plane ◽  
Scanning Force ◽  
Dynamics Simulations

AbstractThe pile up patterns arising in nanoindentation are shown to be indicative of the sample crystal symmetry. To explain and interpret these patterns, complementary molecular dynamics simulations and experiments have been performed to determine the atomistic mechanisms of the nanoindentation process in single crystal Fe{110}. The simulations show that dislocation loops start from the tip and end on the crystal surface propagating outwards along the four in-plane <111> directions. These loops carry material away from the indenter and form bumps on the surface along these directions separated from the piled-up material around the indenter hole. Atoms also move in the two out-of-plane <111> directions causing propagation of subsurface defects and pile-up around the hole. This finding is confirmed by scanning force microscopy mapping of the imprint, the piling-up pattern proving a suitable indicator of the surface crystallography. Experimental force-depth curves over the depth range of a few nanometers do not appear smooth and show distinct pop-ins. On the sub-nanometer scale these pop-ins are also visible in the simulation curves and occur as a result of the initiation of the dislocation loops from the tip.

Sign in / Sign up

Export Citation Format

Share Document