Wednesday, June 20, 2007

Webs, Geckos & Tech

Spiderman, the most popular and soulful creation of Stan Lee and Steve Ditko, has the well known superhuman powers of spider sense and strength, web slinging and the ability to climb walls at a moment's notice. Super strength and sense are still a bit of a stretch but the ability to clone super strong spider silk can become reality because researchers at the University of California, Riverside have recently decoded the genetic sequence of the Black Widow's dragline, something considered to be a landmark achievement as"The black widow spider's dragline silk is a standout compared to other spider silks because of its superior strength and extensibility, a combination which enables black widow dragline silk to absorb enormous amounts of energy." Because spider silk is 4 to 5 times lighter than steel and 5 to 10 times as strong, it's a no brainer as to why people want to create this material by the boatload.As for climbing walls, the Gecko has intrigued scientists and lay people for years as it has the uncanny ability to do just that with ease based on the unique configuration of the lizard's feet as seen by this picture from Wikipedia.Seems that the tiny setae (bristles) on the gecko's feet achieve adhesion via the Van der Waals force which operates via "(electrostatic) interactions between charges. In other words, Wan der Waal forces act, in similar fashion to lightening (albeit in much subtler fashion) as the negative charge of the base of a thunder cloud and the positive charge of the ground becomes so strong that an energy discharge in the form of a lightening bolt happens with terrific force. For the Gecko, the electrostatic adhesion caused by the negative to positive charge attraction from foot to surface occurs at the molecular level given the tiny size of each setae but with millions of setae on each foot, the gecko matches Spiderman's exploits without a problem. With this in mind, RPI & The University at Akron scientists have created Gecko Tape, a prototype material consisting "of polymer surfaces covered with carbon nanotube hairs." The interesting aspect of this tech is that it sticks and unsticks without getting dirty on a wide variety of surfaces, something the Gecko has been doing for millions of years.
Implications of this tech needs no explanation.
Now all we need is super strength and spider sense. Well Mr Wizard, want to give it a go?Postscript. Don Hebert died June 12, 2007. He will be missed as he introduced people like me to the wonders of science way back in the late 50' s.

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