On LightSpray: Inspired By Spiderwebs, Built By Robots, Worn By Marathoners

"The moment we realised this is going to happen, we made it a priority in innovation. This is something so pure and so weird at the same time. This can be revolutionary in so many ways." - Ilmarin Heitz, senior director of innovation at On.

Lighter than many modern smartphones, dramatically more sustainable than standard footwear – the On Cloudboom Strike LS puts the potential future of running shoes at your fingertips.

Discover On LightSpray technology, the secret behind this marathon-winning super shoe which could make lacing up history.

About On Running Shoes

Since the launch of On’s first running shoe, the On Cloudracer, the Swiss brand has been synonymous with innovation. The unique, never before seen technology that set On apart from the pack was CloudTec – a patented, award-winning cushioning system that reacts to your unique stride.

The Cloud elements – specialised pods providing both horizontal and vertical compression – earned hype among the running community, with On’s imagination paying off when it comes to improving the comfort and efficiency of runners. CloudTec transformed the sensation underfoot for runners, with plusher landings and explosive take-offs.

On spread its wings further in the running market, celebrated for its running shoes that offer a cloud-soft ride and smooth shock absorption. On now offer a shoe for every runner - from crushing your everyday training in the floating feel of the On Cloudeclipse, to gliding off-road in the On Cloudultra, to energy-conserving racing shoes like the On Cloudboom Strike for setting a marathon PB.

Further technologies including the propulsive Speedboard and Helion superfoam have ensured On running shoes top the podium in comfort and performance alongside more conventional brands such as Brooks and Asics.

In fact, Asics’ signature Gel technology – known for its reliable durability and cushioned comfort since 1986 - has about a quarter of a century of experience over On’s CloudTec, which launched in 2012 (after winning the ISPO award for innovation in 2010).

But On isn’t about being conventional or linear thinking – they keep pushing the boundaries of what a marriage of innovation and modern technology can bring. In 2024, On’s ingenuity has reached new heights with On LightSpray.

This extraordinary technology applies ingenuity and robotics to produce a feather-light, single-piece and lace-free running shoe upper in just 3 minutes. That's faster than it takes most intermediate runners to run 1km.

The Light Bulb Moment Behind On LightSpray

“I saw there was a quick way of creating a textile onto a complex shape. A shoe seemed to be the right object.” - Johannes Voelchert, innovation design lead at On.

On LightSpray proves that inspiration strikes in unexpected places but can translate to real-world benefits. In the case of On LightSpray, it was a Halloween decoration that started it all.

Johannes Voelchert, now a senior On innovation team member, discovered a video that featured filament-like 'spiderwebs' being crafted from a hot glue gun. Intrigued by how complicated shapes can be forged swiftly from a textile, Johannes presented the idea at the Milan Design Fair in the form of a spray-on shoe.

Martin Ruegg, lead concept designer at On, encountered Johannes' student exhibition featuring an all-white, single-material, single-process shoe - catching his attention for its "revolutionary" possibilities.

Shortly after, On reached out to Johannes. With the inventor and innovator behind this technology on board, On turned its attention to revolutionising running shoe uppers - and the vision behind On LightSpray was born.

From spiderwebs to super shoes, this isn’t the first time On’s innovation has been inspired by the real world. On CloudTec itself, the pivotal technology behind On, was based on a garden hose.

Retired Swiss triathlete Oliver Bernhard, one of On’s co-founders (alongside David Allemann and Caspar Coppetti), stepped on a garden hose purely by accident and discovered he enjoyed the sensation of it rolling beneath his feet. He sought to replicate this buoyant, floating feeling by fusing the cut-up pieces of a garden hose to the soles of his shoes, creating the foundations of CloudTec pods.

On LightSpray: From Vision To Prototype

"Before the '60s basically all shoes were made by hand... The last revolution was 10 or 15 years ago to create the super shoes that we know now. But this is an entirely new way of doing things." - Johannes Voelchert, On Lightspray inventor and innovation design lead at On.

For On LightSpray, the first step was a single-person experiment using a modified, hand-held hot glue gun to develop a prototype. Fast-forward 4 years of development with a passionate team of 20 experts and plenty of trial and error in between – On would use an automated robot arm to create a one-piece, structured upper from a continuous filament – turning a humble vision into reality.

Got 3 minutes to spare? Check out the video above from On.

Yes, robotics was the answer to a spray-on upper, but it couldn’t have been achieved without the creativity of the On innovation team, and the hard work of their expert designers, engineers and computer programmers. "In the end it takes a village to create an innovative and disruptive product and project like this," said Dina Weisheit, sports science lead at On.

Produced at the On Labs in Zurich, each spray-on upper contains 1.5km of semi-translucent monofilament in an engineered helix (spiral) shape. The monofilament is extruded and heat-fused to a performance racing midsole in a continuous stream by On’s built from scratch robot, as it rotates a last. The last is the solid foot form or mould that provides the foundations for the shape of the upper, like a dressmaker's mannequin, but for feet.

"LightSpray is a technology that allows us to very quickly and efficiently in a single process, create an upper that fits like a glove around the foot. The polymers that make up the shoe are truly the building blocks of the technology," shared Eric Hullegie, senior lead of innovation concept design at On.

Hundreds of prototypes and rigorous experimentation supported the development and engineering of the finished product. "The changes that we have between prototypes are sometimes just minuscule. And there was no one in the industry that had ever done it before," said Dina.

The result is a laceless upper that is 30 grams light, created entirely free of glues and seams - with the appearance of an elite running shoe that has shed its skin.

"It's incredibly difficult to make a shoe out of fewer but better materials. With traditional manufacturing methods, sometimes it takes you weeks, if not months, to get an updated prototype again." - Eric Hullegie, senior lead of innovation concept design at On.

The near-finished product is handed to another robot that applies colour. Rather than using conventional dyeing, it uses an automated inkjet printing process to stay honest to On’s sustainability initiatives.

The practicality of a robot-made upper in itself was its own challenge, alongside how that translates to the feel on the athlete’s foot.

A multitude of factors had to be taken into account for On LightSpray to work – from the nuances of the helical structure and how that affects the shoes’ elasticity and breathability, to the heat of the filament, to the speed and distance the robot extrudes and applies it. The ability to fine-tune these elements ensures absolute control in the helix and the final product.

"LightSpray is made for the best athletes in the world. More than anything, we want them to win. That is our gauge of success," said Ilmarin Heitz, senior director of innovation at On.

The manufacturing process allows for precise customisation – creating a soft, second-skin fit for athletes that can comfortably be worn sockless. On take everything from the athlete's unique biomechanics (e.g. foot strike) to their physiology (e.g. oxygen intake when running) into account with a data-driven approach towards achieving speed and efficiency.

"Once they stepped into it, you could see their eyes light up and they're like, 'Wow. I don't want to take this off'," said Dina, On sports scientist.

"By simplifying the amount of materials that we use, we have been able to drastically drop our carbon footprint. It just holds a lot of promise for the future of the footwear industry." - Eric Hullegie, senior lead of innovation concept design at On.

The modern tech meets pure minimalism approach of these spray-on uppers supports higher sustainability – being absent of non-essential bonding materials like glue and manufacturing processes. It means the shoe doesn’t have to cross hundreds of hands before completion. Production can be performed locally, rather than in outsourced factories – shrinking the time gap between manufacture and delivery.

"Usually it's 3 hours for one upper, doing the assembly, stitching them together. The challenge was to cut that down to 3 minutes," said Marie Georgarakis, innovation engineer at On.

If you factor in manufacturing processes that require shipping between various suppliers, it can take days or weeks to produce a standard running shoe upper. With On LightSpray, the Swiss brand essentially cut out the non-essential logistics of creating a running shoe.

In fact, according to On’s website, “This creates the lightest elite-level shoe we’ve ever made. Cutting CO₂ emissions by 75% compared to our other racing shoes.”

The cutting-room floor is free of waste, and the thermoplastic filament of On LightSpray doesn’t need to end at the shoe’s lifespan, being able to be melted and recycled. It’s a bold leap in On’s journey to create circular products, continuously driving towards their ambitious sustainability goals.

On LightSpray: From Prototype To Podium-Topping Performance

On LightSpray’s first introduction to real-world racing has been on an evolution of the On Cloudboom Strike – On’s elite road racing shoes that pair explosive performance with energised bounce.

Heat-fusing the On LightSpray upper onto the performance midsole of the On Cloudboom Strike, On created the fittingly named On Cloudboom Strike LS (LightSpray). The first glances the public received of the simple, swift and sustainable On LightSpray technology in action were on the feet of Kenyan long-distance runner Hellen Obiri in the April 2024 Boston Marathon.

It was a history-making run. Hellen wore a prototype of the On Cloudboom Strike LS when she crossed the finish line – in first place. Not only was this shoe with a spray-bonded upper revolutionary in the sustainability space, but it topped the podium in performance.

Adding to her two silver medals and three major marathon victories (Boston twice and New York), Hellen proudly claimed the bronze medal at the marathon in Paris in August 2024. The inspirational 34 year old athlete crossed the finish line at 2:23:10.

Alike with her most recent Boston Marathon win, the On Cloudboom Strike LS were on her feet for the extraordinary 42.195 km race at Paris - a marathon where athletes endured scorching heat and challenging hills.

Other athletes to adorn the On Cloudboom Strike LS during competition include Australian middle-distance track runner Oliver Hoare and Irish 1,500m runner Luke McCann.

On Cloudboom Strike LS: Simple, Swift & Sustainable

The On Cloudboom Strike LS is fully equipped with everything runners love about the original On Cloudboom Strike – including the energy-returning Helion HF hyper foam and a propulsive carbon fibre Speedboard. The point of difference is the lighter, laceless and seamless On LightSpray upper in the LS model.

On’s eco-conscious approach doesn’t stop at the On LightSpray upper itself, with more than 40% bio-based materials in the snappy Helion HF, a Pebax foam formula.

The total weight of the On Cloudboom Strike LS is 170 grams (6 oz) in the men’s model and 158 grams (5.6 oz) in the women’s model for an incredibly lightweight, barely there and foot-hugging feel.

With a mere 7 components compared to potentially over 30 components of a standard running shoe, On have stripped back the conventional characteristics expected from a running shoe upper – the laces, tongue, toe box, sockliner, strobel and heel cap to name a few – creating a purely sock-like fit.

It is game-changing how such simplicity (with the help of cutting-edge technology) can produce podium-topping results, with the ultra-thin monofilament and sleek, seamless silhouette reducing drag for heightened precision and speed. This hassle-free, slip-on design has naturally earned the attention of triathletes alongside marathoners, for its potential to reduce precious seconds during triathlon transitions.

The On Cloudboom Strike LS benefits aren’t intended to be exclusive to elite athletes either, with a goal to make the revolutionary running shoe accessible to everyday runners as On scale up their LightSpray team – including the robots that made these super shoes possible.

“What motivates me right now is making this technology available for a wider group of people. Hopefully creating a new way of making shoes," said Johannes.

On’s innovation continues, with the On LightSpray robots currently in their fourth generation and evolving in-house with the running shoe brand’s improvements of this pioneering, proprietary technology.

On’s slogan, Dream On, seems a fitting match for this futuristic, convention-breaking technology that combines imagination, innovation and sustainability – a milestone not only for On, but for the running shoe industry as a whole.

On LightSpray inspires the question, are spray-on shoes the future of running? We’re excited to find out.

Please note: According to On's website, the On Cloudboom Strike LS will be available from On later in 2024 and 2025 in selected countries.

If you want to get into the cloud-soft feeling of On running shoes now, shop Sportitude's range today including the On Cloudboom Strike, which features an identical midsole to the LS (LightSpray) edition.

Happy running!