First step towards “programmable materials“
Although the “programmable material” still only works in a one-dimensional model construction, it has already demonstrated it unusual capabilities: The research project entitled Phononic Crystal with Adaptive Connectivity has just been published in the journal Advanced Materials (www.advmat.de). The first step towards mechanical components with freely programmable properties has thus been achieved.
The working model used by the researchers consists of a one-meter by one-centimeter aluminum plate that is one millimeter thick. This sheet-metal strip can vibrate at different frequencies. In order to control the wave propagation, ten small aluminum cylinders (7 mm thick, 1 cm high) are attached to the metal. Between the sheet and the cylinders sit piezo discs, which can be stimulated electronically and change their thickness in a flash. This ultimately enables the team headed by project supervisor Andrea Bergamini to control exactly whether and how waves are allowed to propagate in the sheet-metal strip. The aluminum strip thus turns into a so-called adaptive phononic crystal – a material with adaptable properties.
Adaptation in fractions of a second
The piezo controls can now be set in such a way that waves are able to propagate through the sheet-metal strip “perfectly normally”, i.e. as though no aluminum cylinders were attached to it. Another configuration enables a certain frequency spectrum of the waves to be absorbed. And this muffling is variable as the piezo elements can alter their elastic properties electronically in fractions of a second – from low to high stiffness. Bergamini explains what could develop from the research results: “Imagine you produce a sheet of metal, imprinted with an electronic circuit and small piezo elements at regular intervals. This sheet metal could be programmed electronically to block a certain vibration frequency. The interesting thing is that even if you cut off part of the sheet, the waves in the cropped section would largely spread in the same way as in the initial piece.” This method could be used on three-dimensional components.
Such a “metamaterial” could fundamentally revolutionize mechanical engineering and plant construction. Until now, the vibration properties were already determined in the selection of material and the geometry of the part. In future, the material could react to current vibration readings and adapt its vibration properties at lightning speed.
Further research on “programmable materials“
During the Phononic Crystal with Adaptive Connectivity research project, Empa-researcher Bergamini collaborated with Paolo Ermanni’s group at ETH Zurich and Massimo Ruzzene from Georgia Institute of Technology. In a follow-up project, the programmability of the prototype is to be expanded: “Until now, every piezo element has reacted to vibrations alone, independent of its neighbor,” explains Bergamini. “As the next step, we want to interconnect the elements with each other to be able to control them jointly or in a coordinated fashion.”
Info: Metamaterials (Wikipedia - http://en.wikipedia.org/wiki/Metamaterial)
Metamaterials are artificial media structured on a size scale smaller than the wavelength of external stimuli. Materials of interest exhibit properties not found in nature, such as negative index of refraction. They are cellular assemblies of multiple elements fashioned from materials including metals and plastics, arranged in periodic patterns. Metamaterials gain their properties not from their constituents, but from their exactingly-designed structures. Their precise shape, geometry, size, orientation and arrangement can affect light or sound in a manner that is unachievable with conventional materials.
Dr. Andrea Bergamini | newswise
Nanoscientists develop the 'ultimate discovery tool'
24.06.2016 | Northwestern University
Researchers find better way to 'herd' electrons in solar fuel devices
21.06.2016 | University of British Columbia
Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.
Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...
A year and a half on the outer wall of the International Space Station ISS in altitude of 400 kilometers is a real challenge. Whether a primordial bacterium...
Researchers at Case Western Reserve University have developed a way to swiftly and precisely control electron spins at room temperature.
A physics experiment performed at the National Institute of Standards and Technology (NIST) has enhanced scientists' understanding of how free neutrons decay...
Chemically the same, graphite and diamonds are as physically distinct as two minerals can be, one opaque and soft, the other translucent and hard. What makes...
09.06.2016 | Event News
24.05.2016 | Event News
20.05.2016 | Event News
24.06.2016 | Materials Sciences
24.06.2016 | Physics and Astronomy
24.06.2016 | Physics and Astronomy