U.S. engineers study ancient fish for future body armor

William Atkins
Monday, 28 July 2008 22:46

Science - Biology

The study of the dinosaur eel could lead, according to the MIT authors, to the development of light but bomb-proof body armor for military soldiers. In fact, the U.S. Army is backing the study by these MIT scientists.

The MIT engineers used nano-scale (very tiny) measurements to observe several scales that had been removed from the fish. The scales, only about 0.5 nanometer (about 500 millionth of a meter in thickness(, contain four layers. The engineers subjected the scales to a simulated fish attack whose purpose was to approximate the bite from another fish onto the scales.

The MIT team of engineers concluded that the protection from the scales, especially the overlapping nature of the scales, is very effective due to the different composite materials involved within the scales, along with the geometry and thickness of each layer.

The research team at MIT called the design "fascinating, complex and multiscale.” [AFP: "'Dinosaur eel' points to body armour of the future” ]

In fact, one team member, MIT associate professor Christine Ortiz, head of the Ortiz Laboratory, stated, "Such fundamental knowledge holds great potential for the development of improved biologically-inspired structural material. Many of the design principles we describe—durable interfaces and energy-dissipating mechanisms, for instance—may be translatable to human armour systems." [AFP]
 
The abstract concluded, “The mechanistic origins of penetration resistance (approximating a biting attack) were investigated and found to include the juxtaposition of multiple distinct reinforcing composite layers that each undergo their own unique deformation mechanisms, a unique spatial functional form of mechanical properties with regions of differing levels of gradation within and between material layers, and layers with an undetectable gradation, load-dependent effective material properties, circumferential surface cracking, orthogonal microcracking in laminated sublayers and geometrically corrugated junctions between layers.”

The paper citing the conclusions by the MIT team is called “Materials design principles of ancient fish armour.” It appeared Sunday, July 27, 2008, in the journal Nature Materials.

Its authors are Benjamin J.F. Bruet, Juha Song, and Christine Ortiz (all of the Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A.), and Mary C. Boyce (Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A.).