With New York City’s biggest marathon later this week, On is showing off its innovative new performance shoes and the technology behind them at a 10-day pop-up in NYC. On Saturday, On kicked off the event with a party demonstrating how its robot uses LightSpray™ technology to create a shoe with no laces, glue, or seams. The shoe was famously worn by athlete Hellen Obiri when she won the 2024 Boston Marathon and Bronze medal at the Paris Olympics.

It was hard not to be drawn towards the robot, which sat pride of place at the event in a glass case taller than most people, as it created a Cloudboom Strike LS shoe.

On’s innovation technology design lead Johannes Voelchert, who has worked on the LightSpray™ project for five years, demonstrated the robot and explained how it creates a Cloudboom Strike LS using the technology.

“LightSpray™ is a process where we transform a polymer pellet in three minutes into a fully functional performance shoe,” said Voelchert.

This is done by inserting the mold (known as a last) and the midsole into the unit. The robot starts by establishing a connection between the midsole and what will be the upper part of the shoe, which it creates by spraying a filament made of the polymer pellets onto the last, Voelchert went on to explain.

On says that using LightSpray™ to create the upper reduces the number of parts needed to make a shoe—with their first-to-market shoe, the Cloudboom Strike LS made of seven parts instead of the usual 30 or so. This has reduced carbon emissions for the upper part of the shoe by 75 percent compared to its other racing shoes, according to On.

“Combining this unique spraying technology with robotics enables us to really control every part of the shoe by speeding up, slowing down, and then influencing elasticity, support, and breathability,” Voelchert said.

The Cloudboom Strike LS is the first shoe featuring LightSpray™ technology and, as a result, is also On’s lightest performance shoe, with the company saying it weighs in at 170 grams (6 ounces).

On representatives at the event helped attendees try on the Cloudboom Strike LS shoes, explaining the best way to put them on. This required pulling the sides of the upper outward, sliding the foot all the way to the front of the shoe, and then pulling on the back of the upper so it fits snugly around the ankle.

Event attendees could be seen walking around in front of the robot wearing the Cloudboom Strike LS shoes, talking about how light they felt and how unique the tread is for a performance shoe. The main topic of discussion, however, was the robot and LightSpray™ technology, with guests excited about all the ways it can be used in the future to innovate other types of shoes—and potentially industries.

On's Cloudboom Strike LS shoes will be available for members to purchase at On Labs NYC on October 30th. To learn about future product drops sign up at on.com/lightspray. Check out the On Labs NYC until November 4.