Generally, if there is a window that goes around the right-angle corner of a building, it is made of two individual flat panes of glass that are glued together through a metal rail. Now, German scientists from the Fraunhofer Institute have developed a method to bend a single sheet of glass to a 90° angle without affecting its optical properties. 

They begin with preheating a flat pane of glass to about 500 ºC (932 ºF) which is just below the glass malleable “transition point”. The supports in the oven will prevent the glass from deformations. A mirror-guided laser is then used to heat the glass along a straight line going down the middle of the sheet (softened accordingly) while the rest of the pane remains at 500 ℃. When the supports are removed from beneath one side of the pane, gravity makes the sheet bend along the softened line, naturally going to a 90° angle. Once the glass cools, it becomes rigid again.

As of now, the scientists have been able to make panes measuring a maximum of one square meter (10.8 sq ft) in the lab with their current available equipment. However, they are currently looking for commercial partners in order to make larger sheets.

It is hoped that the processing technology and the product may find applications not only in architecture but also in the medical field where it could be used to produce gap-free glass surfaces that are resistant to bacterial reproduction.