January 21st, 2014
University of California – Berkeley
A new development by researchers at the University of California, Berkeley, could lead to curtains and other materials that move in response to light, no batteries needed.
A research team led by Ali Javey, associate professor of electrical engineering and computer sciences, 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 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. 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. The plastic expands in response to the heat, while the nanotube layer does not, causing the two-layered material to bend. Curtains made of this material could automatically open or close during the day.
The curtains would respond to light, automatically closing when the sun’s rays are their strongest. The smart curtains work without batteries, electricity, or an operating system, which could save large office buildings significantly in energy costs.