Whatsupic -- Remote controlled curtains may become a thing of the past. Researchers at the University of California, Berkeley, have developed new materials that could move curtains in response to light without the need of batteries.
Carbon nanotubes layered on a plastic polycarbonate membrane were used by Ali Javery’s research group creating a material that quickly moves in response to light. It only takes fractions of a second for the nanotubes to absorb light and convert it into heat which is then transferred to the polycarbonate membrane. The heat causes the plastic to expand. The nanotube layer remains firm, while the expansion of the plastic causes the two-layered material to bend.
Javey, an associate professor of electrical engineering and computer sciences at Berkeley, explains: “the advantage 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. The light from a flashlight is enough to generate a response.” The results of the research have been published in the journal Nature Communications this week.
Tweaking the size and chirality of the nanotube –referring to the direction of the twist- makes the material react to different light wavelengths. The flick of a light switch could cause these “smart curtains” to bend or straighten. “We envision these in future smart, energy-efficient buildings,” said Javey. “Curtains made of this material could automatically open or close during the day.”
The applications of such materials are not limited to curtains, and could include light-driven motors and robotics that move in the presence or absence of light. The following video, courtesy the Javey Research Group, demonstrates experimental operation of the novel smart curtain material:
http://www.youtube.com/watch?v=vBs8hYtT48s&feature=youtu.be
Journal reference:
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, and Ali Javey. Photoactuators and motors based on carbon nanotubes with selective chirality distributions. Nature Communications, 2014; 5 DOI: 10.1038/ncomms3983