There’s a weirdly fascinating video that accompanies this research into light-activation and carbon nanotubes,
A Jan. 10, 2014 news item on Nanowerk provides an explanation,
A research team led by Ali Javey, associate professor of electrical engineering and computer sciences [University of California at Berkeley], layered carbon nanotubes – atom-thick rolls of carbon – onto a plastic polycarbonate membrane to create a material that moves quickly in response to light. Within fractions of a second, the nanotubes absorb light, convert it into heat and transfer the heat to the polycarbonate membrane’s surface. The plastic expands in response to the heat, while the nanotube layer does not, causing the two-layered material to bend.
The Jan. 9, 2014 University of California at Berkeley research brief by Sarah Yang, which originated the news item, provides some perspective from lead researcher Javey and a few more details about the research,
“The advantages of this new class of photo-reactive actuator is that it is very easy to make, and it is very sensitive to low-intensity light,” said Javey, who is also a faculty scientist at the Lawrence Berkeley National Lab. “The light from a flashlight is enough to generate a response.”
The researchers described their experiments in a paper published this week in the journal Nature Communications. They were able to tweak the size and chirality – referring to the left or right direction of twist – of the nanotubes to make the material react to different wavelengths of light. The swaths of material they created, dubbed “smart curtains,” could bend or straighten in response to the flick of a light switch.
“We envision these in future smart, energy-efficient buildings,” said Javey. “Curtains made of this material could automatically open or close during the day.” [emphasis mine]
Other potential applications include light-driven motors and robotics that move toward or away from light, the researchers said.
Here’s a link to and a citation for the paper,
Photoactuators and motors based on carbon nanotubes with selective chirality distributions by Xiaobo Zhang, Zhibin Yu, Chuan Wang, David Zarrouk, Jung-Woo Ted Seo, Jim C. Cheng, Austin D. Buchan, Kuniharu Takei, Yang Zhao, Joel W. Ager, Junjun Zhang, Mark Hettick, Mark C. Hersam, Albert P. Pisano, Ronald S. Fearing, & Ali Javey. Nature Communications 5, Article number: 2983 doi:10.1038/ncomms3983 Published 07 January 2014
The earlier reference to energy-efficient buildings suggests that this work with light-activated curtains is another variation of a ‘smart’ window’ and bears some resemblance to Boris Lamontagne’s (Canada National Research Council) work with curling electrodes which act as blinds in his version of smart glass as per my .Sept. 16, 2011 posting.
Ali Javey has been mentioned here before in a Sept. 15, 2010 post concerning nanotechnology-enabled robot skin.