Making smartphones smarter with see-through sensors!

A new technique can allow phone displays to be embedded with layer upon layer of sensors, including ones that could take your temperature, assess your blood sugar levels if you're diabetic or even analyse DNA.
Researchers, including one of Indian-origin, have created the first laser-written light-guiding systems that are efficient enough to be developed for commercial use.
This new technique could allow the phone display to be embedded with layer upon layer of see-through sensors, enabling applications like temperature sensors and biomedical monitors to be manufactured directly into the display.
The researchers have used their new technology to build two completely transparent systems - a temperature sensor and a new system for authenticating a smartphone using infrared light - into a type of glass that's currently used in most smartphones.

In addition to biomedical sensors, the technology could also eventually allow computing devices to be embedded into any glass surface, such as windows or tabletops, creating the transparent touchscreens seen in movies like Avatar and Iron Man, researchers said.
"We're opening the Pandora's box at the moment," said study co-author Raman Kashyap, a professor of electrical engineering and engineering physics at Polytechnique Montreal in Canada.

Now that the technique is viable, "it's up to people to invent new uses" for it, he said.
To make their see-through temperature-sensing and phone-authentication systems, the researchers turned to photonics. While electronic devices transmit information via electrons, photonic devices use light.

The researchers, collaborating with the New York-based company Corning Incorporated, used lasers to carve out transparent pathways called waveguides into the glass.
These waveguides act as tunnels that channel light, analogous to the way electronic wires convey electrical signals, and form the basis for a host of applications.
Although people have used lasers to make photonic waveguides before, this is the first time anyone has applied the technique to Gorilla Glass, a tough glass with high internal stress and low irregularity.
According to first author of the study Jerome Lapointe of Polytechnique Montreal, this new photonic waveguide is the best that's ever been made using lasers.

While no waveguide is perfect - light will inevitably leak out due to imperfections - the new waveguides created by the team are 10 times better at minimising such loss than previous ones made with lasers, Lapointe said.
Using lasers enables researchers to make waveguides at any depth, allowing them to create many applications, one on top of each other, like layers in a cake.
Layering the waveguides within the glass itself paves the way for more compact devices, which means you could squeeze more apps into your phone, researchers said.
The work is published in The Optical Society's (OSA) open-access journal, Optics Express.