Cutting-edge technology led to the creation of the LightSpray running shoe, but it may not be the tech you’re thinking of. Johannes Voelchert watched a video of a Halloween hot glue gun spraying spider webs and was inspired to create something. In the end, it became the LightSpray shoe.

Voelchert, in London with the robot that will build a shoe in front of your eyes in around four minutes, says that he didn’t immediately know he’d use the inspiration to build shoes (“It could have been a lampshade at one point,” he said).

But in the end, he pitched the idea of a shoe to On, the Swiss running shoe company, who gave him a job. The result is the shoe that tech built: laceless, with a one-piece upper and created in an entirely new automated method. Voelchert is now On’s Innovation Technology Design Lead.

How The LightSpray Robot Works

The robot swings the shoe sole and what looks like a blue gumboot in front of a single thread of continuous filament. Using artful robotic movements of the sole, the filament sprays the upper into place on the gumboot (that part is later removed). Minutes later, the robot starts on the next shoe. In between, a tiny pile of what looks like gossamer-light snow builds up on the ground.

If I’m making the whole thing sound a little hypnotic to watch, that’s because it is, and it’s on show until Sunday in central London as part of an immersive experience with movement sessions and workshops. There’s also a pre-Marathon party on April 24 and a recovery lounge on April 26.

Right now, the robot is building, with its charmingly quiet indefatigability, the On LightSpray Cloudmonster 3 Hyper and Lightspray Cloudboom Strike. Visitors can try each of the shoes on and buy them from On’s Regent Street store, just round the corner from the special event.

Marathon Performance And Sustainability

The Cloudboom Strike is the shoe worn by Hellen Obiri when she won the New York City Marathon in record time. Obiri was also at the central London event, looking relaxed and confident before she takes part in the London run.

Voelchert said that while it wasn’t on the official roadmap he wasn’t against the idea of licensing the tech to other companies. Along with the sheer innovation, there’s a sustainability aspect here: the few minutes of filament spray creates uppers with fewer carbon emissions: up to 65% fewer emissions when manufacturing the LightSpray Cloudmonster 3 Hyper upper, for instance.

The events run until Sunday, April 26 and to register, sign up here .