February 21, 2013

Researchers ‘Nanoweld’ by Applying Light to Aligned Nanorods in Solid Materials

Researchers from North Carolina State University have developed a way to melt or “weld” specific portions of polymers by embedding aligned nanoparticles within the materials. Their technique, which melts fibers along a chosen direction within a material, may lead to stronger, more resilient nanofibers and materials.

Physicists Jason Bochinski and Laura Clarke, with materials scientist Joe Tracy, placed specifically aligned gold nanorods within a solid material. Gold nanorods absorb light at different wavelengths, depending upon the size and orientation of the nanorod, and then they convert that absorbed light directly into heat. In this case, the nanorods were designed to respond to light wavelengths of 520 nanometers (nm) in a horizontal alignment and 800 nm when vertically aligned. Human beings can see light at 520 nm (it looks green), while 808 nm is in the near infrared spectrum, invisible to our eyes.