Spiky cones make glass virtually reflection-free

Spiky cones make glass virtually reflection-free
A sample of the nanotextured glass (left), as compared to an untreated sample
A sample of the nanotextured glass (left), as compared to an untreated sample
View 1 Image
A sample of the nanotextured glass (left), as compared to an untreated sample
A sample of the nanotextured glass (left), as compared to an untreated sample

Whether they're on smartphone displays or TV screens, reflections can be a nuisance. US Department of Energy scientists working at Brookhaven National Laboratory, however, have reportedly found a way of almost eliminating them. It involves treating regular glass surfaces by etching tiny nanoscale cones into them.

Reflections occur whenever light encounters an abrupt change in refractive index – that's the degree to which a ray of light bends as it goes from one material to another, such as moving from air to water.

By etching the glass' surface into "a forest of nanoscale cone-shaped structures with sharp tips," the change of refractive index for light passing from the air into that glass is made much more gradual than it would be otherwise. Reflections are thus reduced by so much that the glass is claimed to be rendered almost invisible, across the entire visible and near-infrared spectrum and from a wide range of viewing angles.

Along with its use on electronic devices such as smartphones, the technology could also make solar cells more efficient, as more light would go into them instead of being reflected off.

In a lab test, the researchers compared the performance of one solar cell without a cover, one with a conventional glass cover, and one with a cover made from the nanotextured glass. The cell with the treated glass produced as much electricity as the uncovered cell, while the one covered with regular glass produced less.

The scientists are now looking towards commercializing the technology. A paper on the research was recently published in the journal Applied Physics Letters.

Source: Brookhaven National Laboratory via EurekAlert

Awesome! I await the flood of security camera footage with people leaving Starbucks with latte in hand as they walk into glass doors spilling their hot beverages over themselves.
Bruce H. Anderson
This seems similar to cone mats put in urinals to prevent spattering, where the object is to "de-spatter" light instead of urine. There was also the world's blackest surface that was created some time back, where the surface was etched to gather rather than reflect light. The nano-cones would provide a more consistent product perhaps. The article does not address how easy it is to clean. I can't help wondering if the nano-cones might get filled up with skin oils etc. after a short while, or if they would wear down.
HP made a color vector graphics computer monitor for the Rocky Mountain Basic Workstation that had an anti-reflection coating. But . . . . . there was a problem with fingerprints causing Moire type color gringes. I wonder what happens when fingers touch the screen?
Adding to Bruce's comment, I worry about disinfection. Cleaning in a hospital environment would be questionably challenging. Or any place where food production took place.
Google "Spiky surfaces kill bacteria" there may be a way to incorporate both kinds of cones on the glass or maybe they are already the same size/shape to kill bacteria.