The success of many advanced technologies that use devices such as sensors and actuators, including gyroscopes and optical devices, depends on microscopic components called microelectromechanical systems (MEMS) devices made of polycrystalline silicon (polysilicon). Researchers at Case Western Reserve University report in the November 8 issue of Science that miniature micron-sized polysilicon laboratory specimens subjected to cyclic tension/compression loading undergo fatigue, and could ultimately fail as a result of damage produced by the compressive cycles, rather than from moisture-assisted stress corrosion cracking. This information, they say, could assist MEMS developers to mitigate fatigue failure in MEMS devices that experience significant mechanical stress during operation.
The Science article ("Fatigue Failure in Polysilicon: It’s Not Due to Simple Stress Corrosion Cracking") was written by Harold Kahn, Research Associate Professor in the department of materials science and engineering; Roberto Ballarini, Professor in the department of civil engineering and a lead researcher on the project; Arthur Heuer, University Professor and Kyocera Professor of Ceramics in the department of materials science and engineering; and Justin Bellante, a recent BS/MS graduate of materials science and engineering.
Polysilicon, CWRU researchers say, is a manufactured thin film consisting of silicon crystallites that is made in a microfabrication laboratory using chemical vapor deposition. The films are associated with rough surfaces that result from the plasma etching used in the final stages of MEMS processing. The researchers speculate that under compressive loading, these surfaces come into contact, and their wedging action produces microcracks that grow during subsequent tension and compression cycles.
Marci E. Hersh | EurekAlert!
Novel sensors could enable smarter textiles
17.08.2018 | University of Delaware
Quantum material is promising 'ion conductor' for research, new technologies
17.08.2018 | Purdue University
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
17.08.2018 | Materials Sciences
17.08.2018 | Information Technology
17.08.2018 | Physics and Astronomy