Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cornell researchers test carbon fiber to make tiny, cheap video displays

24.08.2006
Engineers who develop microelectromechanical systems (MEMS) like to make their tiny machines out of silicon because it is cheap, plentiful and can be worked on with the tools already developed for making microelectronic circuits. There is just one problem: Silicon breaks too easily.

For decades, researchers have been trying to make video displays using tiny mirrors mounted on silicon oscillators. But silicon won't oscillate fast enough and bend far enough.

"You need something incredibly stiff to oscillate at a resonant frequency of 60,000 times a second (the line-scanning rate of most video displays), but it also needs to bend a lot for adequate image size," explained Shahyaan Desai, a Cornell graduate student who has been working for more than three years to create a practical MEMS video display device.

So Desai and his Cornell colleagues have turned to carbon fiber, the same material used to reinforce auto and aircraft body parts, bicycle frames and fishing rods.

"Carbon fiber is twice as stiff as silicon but 10 times more flexible," said Desai.

He is first author of a paper with Michael Thompson, Cornell associate professor of materials science and engineering, and Anil Netravali, Cornell professor of fiber science, on using carbon fibers in MEMS, published in the July issue of the Journal of Micromechanics and Microengineering.

Carbon fibers are made of thin, narrow sheets of graphite that roll up and clump together to form fibers. For industrial uses the fibers are embedded in plastic to form composite materials that are stronger than steel, yet lighter. Desai's MEMS are made with the raw fibers.

Desai first showed that micrometer-scale carbon fibers can bend like tiny fishing rods by more than 90 degrees and can be made to vibrate billions of times without breaking down. "This is, to our knowledge, the first material to even approach such large deformation at high frequencies without observable fatigue," the researchers wrote in their paper.

"Carbon is normally a brittle material," Desai said, "but in the fiber form it resists breakage. We have some data implying that if it lasts three and a half days it's going to last forever."

Desai then built an optical scanner consisting of a tiny rectangular mirror measuring 400 by 500 microns, supported by two carbon-fiber hinges about 55 microns across. Made to oscillate at 2.5 kHz, the tiny mirror caused a laser beam to scan across a range of up to 180 degrees, corresponding to a 90-degree bend by the carbon fibers.

An oscillating mirror could be used to scan a laser beam across a screen, and an array of mirrors, one for each horizontal line, could produce an image in the same way that a moving electron beam creates an image on a television screen.

"It would be an incredibly cheap display," Desai said. And the entire device would be small enough to build into a cell phone to project an image on a wall.

Besides serving as oscillators, the researchers said, carbon fibers could be made into clock springs that either unwind slowly to power a micromachine over a period of time or unwind rapidly to provide a sudden burst of power, or used as micro-sized pendulums that could harvest energy from motion like a mechanical self-winding watch to make cell phones, PDAs and even watches that are powered by the user's movement.

| EurekAlert!
Further information:
http://www.cornell.edu

More articles from Materials Sciences:

nachricht New approach to revolutionize the production of molecular hydrogen
22.05.2017 | Technische Universität Dresden

nachricht Photocatalyst makes hydrogen production 10 times more efficient
19.05.2017 | Kobe University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

 
Latest News

New approach to revolutionize the production of molecular hydrogen

22.05.2017 | Materials Sciences

Scientists enlist engineered protein to battle the MERS virus

22.05.2017 | Life Sciences

Experts explain origins of topographic relief on Earth, Mars and Titan

22.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>