Custom Search

Wednesday, November 11, 2009

Mimicking the Building Prowess of Nature

Scientists build new materials using inspiration from complex biological forms.

Joanna Aizenberg, a materials scientist at Harvard University, has scoured the natural world for clues to biological building codes. She aims to decipher some of Mother Nature’s unique designs, including dirt-resistant sea urchins and sea sponges made of super-strong light-conducting glass, to develop novel materials that, like these organisms, can self-assemble and sense and respond to their environment.

“We try to identify biological systems that have unusual and sophisticated properties, such as optical, structural, or magnetic properties, to make extremely sophisticated, efficient, and highly potent devices and materials,” says Aizenberg, who is also a core faculty member at the Wyss Institute for Biologically Inspired Engineering. “Then we take these principles and try to integrate them with what we already know in materials science--incorporating them into existing materials or fabricating a new generation of materials based on biological principles.” The work could result in better fiber optics, paint that changes color in response to temperature or light, and new ways of delivering drugs or clearing arterial plaques.

This collection of striking images explores some of Aizenberg’s new materials, as well as the organisms that inspired them.

Nanodreadlocks: “One specific feature that interests me more than anything else at the moment is how nature creates adaptive materials that optimize performance in response to changing environmental cues,” says Aizenberg. “The systems I am trying to replicate in my lab are the surfaces of sea urchins. They cover their bodies with an array of microflowers that constantly open and close, protecting the body from contamination.”

Taking inspiration from sea urchins, Aizenberg’s team has developed nanobristles that spontaneously curl into a precise array of helical bundles when immersed in an evaporating liquid. Aizenberg likens the phenomena to the way wet, curly hair clumps together and coils to form dreadlocks. The bristles shown here are made of an epoxy resin and are approximately 100 nanometers in diameter--about one-thousandth the width of a human hair.

No comments:

Post a Comment