MEMS

For more than 15 years, carbon nanotubes (CNTs) have been the flagship material of nanotechnology. Researchers have conceived applications for nanotubes ranging from microelectronic devices to cancer therapy. Their atomic structure should, in theory, give them mechanical and electrical properties far superior to most common materials.  

Adelaide, Australia, August 24 - 29, 2008

Final Announcement and Call for Papers

http://ictam2008.adelaide.edu.au

Laguna Beach, CA March 31, 2007 -- Kebaili Corporation a leading California based high-tech company announced today the release of the CPG-500 Series, the industry first compact current pulse generator, specifically designed for electrodeposition applications, such as (direct current) DC plating, pulse plating, and periodic reverse pulse plating for a variety of applications in MEMS and nanotechnology.

We report the loading and unloading force response of single living adherent fibroblasts due to large lateral indentation obtained by a two-component microelectromechanical systems (MEMS) force sensor. Strong hysteretic force response is observed for all the tested cells. For the loading process, the force response is linear (often with small initial non-linearity) to a deformation scale comparable to the undeformed cell size, followed by plastic yielding. In situ visualization of actin fibers (GFP) reveals that during the indentation process, actin network depolymerizes irreversibly at discrete locations to form well-defined circular actin agglomerates all over the cell, which explains the irreversibility of the force response. Similar agglomeration is observed when the cell is compressed laterally by a micro plate. The distribution pattern of the agglomerates strongly correlates with the arrangement of the actin fibers of the pre-indented cell. The size of the agglomerates increases with time as ta  with a= 2~3 initially,   followed by a=.5~1. The higher growth rate suggests influx of actin into the agglomerates. The slower rate suggests a diffusive spreading, but the diffusion constant is two orders of magnitude lower than that of an actin monomer through the cytoplasm. Actin agglomeration has previously been observed due to biochemical treatment, gamma-radiation, and ischemic injury, and has been identified as a precursor to cell death. We believe, this is the first evidence of actin agglomeration due to mechanical stimuli. The study demonstrates that living cells may initiate similar functionalities in response to dissimilar mechanical and biochemical stimuli.

It is well-recognized that MEMS switches, compared to their more traditional solid state counterparts, have several important advantages for wireless communications.  These include superior linearity, low insertion loss and high isolation.  Indeed, many potential applications have been investigated such as Tx/Rx antenna switching, frequency band selection, tunable matching networks for PA and antenna, tunable filters, and antenna reconfiguration. 

However, none of these applications have been materialized in high volume products to a large extent because of reliability concerns, particularly those related to the metal contacts.  The subject of the metal contact in a switch was studied extensively in the history of developing miniaturized switches, such as the reed switches for telecommunication applications.  While such studies are highly relevant, they do not address the issues encountered in the sub 100mN, low contact force regime in which most MEMS switches operate.  At such low forces, the contact resistance is extremely sensitive to even a trace amount of contamination on the contact surfaces.  Significant work was done to develop wafer cleaning processes and storage techniques for maintaining the cleanliness.  To preserve contact cleanliness over the switch service lifetime, several hermetic packaging technologies were developed and their effectiveness in protecting the contacts from contamination was examined.  

Ninth U.S. National Congress on computational mechanics
July 22 -26, 2007. San Francisco, California

A mini-symposium on

COMPUTATIONAL METHODS FOR MICRO AND NANO SYSTEMS

Call for Papers
Micro and Nano Electro Mechanical Systems have recently attracted much attention from the industry and from the scientific community. MEMS are nowadays routinely met in various fields like in the automotive, aerospace and large consumer applications.
It can be said that for various micro systems the pioneering phase has been substituted by a phase of industrial applications. Hence, new challenges concerning reliability, optimization and increasing miniaturizations must be tackled by the designers. All these issues need a multi-disciplinary approach and must be supported by multi-physics numerical and experimental analyses able to contribute to the definition of a unified design and analysis methodology of MEMS and NEMS.

Dear Colleagues:

The 13th International Conference on Experimental Mechanics (ICEM13, http://www.icem13.gr) will be held on July 1-6, 2007 in Alexandroupolis, Greece. It is our pleasure to announce that the Conference will include a special symposium organized by us entitled, “Plasticity, Fracture and Fatigue at the Micro and Nano Scales,” which will focus on recent developments in this area within the larger scope of assessing research needs in a variety of applications of interest.