July 11, 2012

Smart materials get SMARTer



(July 11, 2012)  Living organisms have developed sophisticated ways to maintain stability in a changing environment, withstanding fluctuations in temperature, pH, pressure, and the presence or absence of crucial molecules. The integration of similar features in artificial materials, however, has remained a challenge—until now.

In the July 12 issue of Nature, a Harvard-led team of engineers presented a strategy for building self-thermoregulating nanomaterials that can, in principle, be tailored to maintain a set pH, pressure, or just about any other desired parameter by meeting the environmental changes with a compensatory chemical feedback response.

Called SMARTS (Self-regulated Mechano-chemical Adaptively Reconfigurable Tunable System), this newly developed materials platform offers a customizable way to autonomously turn chemical reactions on and off and reproduce the type of dynamic self-powered feedback loops found in biological systems.


The advance represents a step toward more intelligent and efficient medical implants and even dynamic buildings that could respond to the weather for increased energy efficiency. The researchers also expect that their methodology could have considerable potential for translation into areas such as robotics, computing, and healthcare.

Structurally, SMARTS resembles a microscopic toothbrush, with bristles that can stand up or lie down, making and breaking contact with a layer containing chemical ‘nutrients’.

“Think about how goosebumps form on your skin,” explains lead author Joanna Aizenberg, Amy Smith Berylson Professor of Materials Science at the Harvard School of Engineering and Applied Sciences (SEAS) and a Core Faculty Member at the Wyss Institute for Biologically Inspired Engineering at Harvard. “When it is cold out, tiny muscles at the base of each hair on your arm cause the hairs to stand up in an insulating layer. As your skin warms up, the muscles contract and the hairs lie back down to keep you from overheating. SMARTS works in a similar way.”

read entire press release >>