Innovations
INNOVATIONS: Robot etched windows fix mobile signal dead zones in buildings
In the race to create energy-efficient buildings, one detail has been overlooked — and it’s costing connectivity. While modern glass coatings keep heat in and energy bills down, they’re also blocking mobile phone signals, turning cutting-edge office towers and homes into digital dead zones. But a novel robotic solution developed by HEGLA Boraident could offer an elegant fix: restoring mobile signal without compromising sustainability.
At the heart of the issue is low-emissivity (low-E) glass — a mainstay of contemporary architecture. These windows are coated with a transparent, metallic layer that reflects infrared radiation, significantly improving a building’s thermal insulation. However, that same coating is proving a barrier to something else: radio signals.
“The coating dams the radiation for the cell phone,” explains Thomas Rainer of HEGLA Boraident. What was designed to shield occupants from thermal loss inadvertently blocks electromagnetic frequencies, including those used by mobile networks. The result is a phenomenon well-known to many — full signal outdoors, and none once you step inside.
This creates a painful dilemma for developers and property owners. After investing heavily in sustainable designs and retrofitting old buildings for energy efficiency, they’re confronted by a fundamental flaw. “Nobody knows about the fact that the coating dams the radiation,” Rainer says. “Then the first people are in the building and see, ‘Okay, I have no possibility to get a call from outside.’ And then starts the problem.”
A precise, retrofit solution
Previously, addressing the issue meant adding internal signal boosters or replacing the windows — expensive, invasive solutions. Now, HEGLA Boraident’s new robotic system offers a precise and non-disruptive alternative.
The system, described by its developers as a “Cobot device”, works by structurally altering — not removing — the low-E coating. Using a smart laser process, it etches a subtle, almost invisible pattern onto the glass, creating microscopic pathways through which radio signals can pass. Thermal performance remains largely intact.
What sets the device apart is its speed and simplicity. “A typical process time for such a window, a square meter or something like this, is 10 minutes,” says Rainer. Within minutes, a previously signal-blocking pane is transformed into a conduit for connectivity.
Initially conceived as a fix for already-occupied buildings suffering unexpected signal loss, the technology is now catching the attention of architects and developers at the design stage. “We saw in the last time… that also the architects have some interest on this system, even if they are building a new building,” says Rainer.
This shift in approach suggests that mobile signal optimisation could soon be integrated into building planning, rather than applied reactively after complaints arise. For developers, this offers not just technical efficiency but also reputational insurance: avoiding the growing frustration of disconnected tenants and workers.
HEGLA Boraident is already thinking beyond signal restoration. Future versions of the device may include additional printing heads, enabling new functionalities on glass surfaces — potentially transforming windows into smart interfaces.
As sustainable construction becomes the global norm, innovations like this are likely to play a pivotal role in bridging the gap between energy efficiency and technological convenience. By turning a once-inert window into an intelligent, adaptable surface, the Cobot not only solves a modern architectural problem — it reshapes the expectations of what a window can do.
In the balance between green credentials and digital demands, this compact robotic solution offers a compelling middle ground. It allows modern buildings to retain their low-energy profile while staying open to the signals of the outside world — a quiet, precise answer to a problem hidden in plain sight.
E: thomas.rainer@hegla-boraident.de
Why This Matters: Innovation like this pushes the boundaries of the capabilities of glass and windows. A common overlooked problem in buildings has been given the attention it deserves. The resulting solution is just another fine example of the innovation and blue sky thinking that is prevalent in the fenestration sector. Such innovations should be promoted to architects and building designers as they demonstrate the impressive levels of innovation in the glazing sector.
