Dutch engineers at Delft University of Technology have discovered graphene bubbles capable of changing colors while expanding and contracting.
The Dutch team collaborated with Graphnea in Spain to assemble the 13-micrometer wide, balloon-like pixels, which were covered with a double layer of graphene merely two atoms thick.
Oddly enough, the color-changing aspect of the graphene bubbles actually came as somewhat of a disappointment initially because it was very unexpected.
“At first, I was disappointed since I was researching these devices to see if they might have a function as sensors,” Cartamil-Bueno said. “Seeing the colours under a microscope, I realized that the devices were not homogeneous, which is bad if you are trying to create a sensor.”
However, Samer Houri, leader of the research teams, realized the nanodevices were behaving similar to balloons, representing mechanical pixels with the potential to be more durable than current LEDs in the market.
The pressure differences between the cavity and outer atmosphere led to the membrane pushing down toward the bottom of the cavity, promoting color change to occur as result of the difference in lightwaves getting reflected from the membrane’s bottom to its top.
“These devices provide a means to implement display technology based on interferometric modulation,” said Cartamil-Bueno.