{"id":8161,"date":"2013-08-19T15:59:14","date_gmt":"2013-08-19T22:59:14","guid":{"rendered":"http:\/\/cafe.foundation\/blog\/?p=8161"},"modified":"2013-08-19T15:59:14","modified_gmt":"2013-08-19T22:59:14","slug":"lighter-stronger-and-morphable","status":"publish","type":"post","link":"http:\/\/cafe.foundation\/blog\/lighter-stronger-and-morphable\/","title":{"rendered":"Lighter, Stronger, and Morphable"},"content":{"rendered":"

If you have a pre-teen roaming around the house, you more than likely know the shared delight of assembling the biggest possible thing you can make from Lego\u00ae blocks.\u00a0 There must be something of that delight in the Center for Bits and Atoms<\/a> at the Massachusetts Institute of Technology (MIT).<\/p>\n

There, researchers have invented, \u201cA new approach to assembling big structures<\/a> \u2014 even airplanes and bridges \u2014 out of small interlocking composite components,\u201d according to a story by David L. Chandler of the MIT News Office.<\/p>\n

Neil Gershenfeld, director of the Center, and post-doctoral student Kenneth Cheung recently co-authored a paper published in the journal Science<\/i><\/a>, in which they describe assembling strong lightweight structures with \u201ccubocts,\u201d lattice structures that are the lightest and strongest in existence, as stated in the Center\u2019s publications.<\/p>\n

The Center claims 12.3 megaPascals, or 1,784 pound per square inch strength for the 7.3 milligrams per cubic centimeter material (about 0.45 pounds per cubic foot).\u00a0 Balsa wood, by comparison, weighs 4.0 to 13.0 pounds per cubic foot, with far lower tensile or compressive strengths for its weight.<\/p>\n

\"MIT's<\/a>

MIT’s cubocts, essentially repeating, cross-shaped flat pieces arranged in myriad patterns, seen from different perspectives. \u00a0Photo courtesy of Kenneth Cheung<\/p><\/div>\n

These materials also have \u201ctunable and exotic responses to external and internal loads,\u201d making them viable candidates for aircraft parts that could alter their shapes in response to aerodynamic or structural loads.<\/p>\n

Chandler reports, \u201cGershenfeld likens the structure \u2014 which is made from tiny, identical, interlocking parts \u2014 to chainmail. The parts, based on a novel geometry that Cheung developed with Gershenfeld, form a structure that is 10 times stiffer for a given weight than existing ultralight materials. But this new structure can also be disassembled and reassembled easily \u2014 such as to repair damage, or to recycle the parts into a different configuration.\u201d<\/p>\n

Like Legos, the tiny bits can be mass produced (perhaps through 3D printing), and the team is working on a robotic system to assemble them into big items. MIT reports, \u201cThe team is now developing an assembler robot that can crawl, insectlike, over the surface of a growing structure, adding pieces one by one to the existing structure.\u201d<\/p>\n

\"text\"<\/a>

In the lab, a sample of the cellular composite material is prepared for testing of its strength properties. \u00a0Photo courtesy of Kenneth Cheung<\/p><\/div>\n

This avoids the high cost of buildings that need to be constructed to house all the big parts that go into things like airplanes.\u00a0 Boeing created one of the largest structures in the world to contain the production and final assembly of the 747, and Airbus has the problem of shipping huge A380 components on barges and through tiny villages to build a final assembly.\u00a0 Overseas suppliers for 787 components have to construct large factories and solve the problem of hauling big pieces trans-continentally.<\/p>\n

MIT expands on the advantages of CBA\u2019s work.\u00a0 \u201cPound for pound, the new technique allows much less material to carry a given load. This could not only reduce the weight of vehicles, for example \u2014 which could significantly lower fuel use and operating costs \u2014 but also reduce the costs of construction and assembly, while allowing greater design flexibility. The system is useful for \u2018anything you need to move, or put in the air or in space,\u2019 says Cheung, who will begin work this fall as an engineer at NASA\u2019s Ames Research Center.\u201d<\/p>\n

\"NASA's<\/a>

NASA’s concept for an aircraft made with morphing metals, similar to the materials developed at MIT. \u00a0This simulates incompressible turbulent flow over a biologically-inspired configuration<\/p><\/div>\n

Emerging elements of nanotechnology, bio-mimetics and smart material technology could one day allow aircraft to rival the flight control of birds, as suggested by the swift-like morphing of a NASA concept shown above. \u00a0Others are working with conventional materials to exact better performance from even unmanned aerial vehicles, as shown in the video below.<\/p>\n