When footwear testing specialist Heeluxe were looking to change the way shoe fit is measured, they turned to tactile sensing pioneer PPS. Initially, the search was for high precision sensors to help improve shoe fitting, but it has since evolved into a six-year partnership that produced SmartLast, a world-first precision measurement system that replicates and quantifies human shoe-fit perception.

Founder Dr Geoffrey Gray had one simple goal for this technology: make shoe comfort measurable in a way that genuinely reflects how people feel in their shoes.

“We’ve always believed that comfort shouldn’t be guesswork,” Gray explains. “If someone can feel tightness, slipping or pressure, then we should be able to measure it. The challenge is building the right tools and making them work at scale.”

That belief led Heeluxe to explore tactile sensing technology and ultimately connect with PPS. What started as a search for high-precision sensors to support human fit testing soon grew into a long-term development partnership. Together, the companies created SmartLast – the world’s first automated system that can replicate and quantify true human shoe-fit perception.

By combining PPS’s tactile sensing technology with Heeluxe’s biomechanics knowledge, the two teams built a system that delivers laboratory-level accuracy at production speed. SmartLast reduces test time from days or weeks to just 30 seconds, transforming how the world’s footwear is evaluated and refined.

Based in Santa Barbara, California, Heeluxe works with major footwear brands to analyse comfort, performance and fit. In 2014, the company developed a pressure-sensor methodology that captured the human experience of tight and loose fit across different shoe categories. This work led to category-specific standards for running shoes, dress shoes, casual footwear and hiking boots. Within a year, Heeluxe’s fit evaluation method had become one of its most requested services.

However, the success highlighted a fundamental limitation: the approach still depended on human testers. “It worked really well but it simply couldn’t scale,” Gray says. “You can only test so many shoes with real people, no matter how good your process is.”

The role of PPS

PPS partners with industries requiring high-reliability measurement systems. Its collaboration with Heeluxe has evolved from sensor supplier to strategic development partner through a relationship dating back to 2018. Though Heeluxe had extensive experience building custom sensor systems in-house, the team was immediately impressed by PPS’s quality and their customer-focused approach, which prioritised building to real-world requirements rather than pushing technology for its own sake.

Heeluxe was introduced to PPS through a footwear brand already using its sensing technology. When Gray saw PPS’s sensors up close, the decision became clear. “We’ve built our own systems in the past, so we know when hardware is good,” he explains. “PPS’s sensors were more precise, more consistent, and better suited to the kind of measurement we were aiming for.”

Physical proximity played a part too. With Heeluxe in Santa Barbara and PPS in Los Angeles, the teams could work closely, iterate quickly and collaborate in person. “When you’re creating something that’s never existed before, being able to get in the same room, troubleshoot and refine together makes a huge difference,” Gray adds.

Scaling-up from subjectivity

SmartLast was developed in a climate where technology was often viewed with scepticism. “The footwear industry is incredibly small and interconnected,” Gray explains. “There’ve been tools in the past that promised to measure fit and comfort but didn’t hold up in the real world. When that happens, people remember.”

That meant SmartLast had to be exceptionally reliable. “If even one system failed in the field, we’d lose trust immediately,” says Gray. “Reliability wasn’t a target, it was survival.”

PPS helped ensure development stayed focused on practicality and scale. From day one, their approach centred on what Heeluxe and its customers truly needed. 

“PPS never tried to dazzle us with tech for tech’s sake,” Gray says. “They kept us focused on what mattered: performance, consistency and results for brands and their customers. Anytime we drifted toward ‘nice-to-have’ features, they pulled us back.”

“By focusing on practicality, performance, and scalability, PPS helped turn SmartLast from an ambitious idea into a globally deployable system trusted by more than 60 leading footwear brands,” Gray added.

According to Zappos catalogue analysis, a typical timeline for a full human-based testing approach would take 34 years. SmartLast was launched in 2020 after just two years of strategic planning and development.

Today, more than 60 footwear brands use SmartLast annually for fit analysis, with systems deployed not only in California but in Canada, Japan, China, Vietnam, the Czech Republic and the United Arab Emirates. Alongside SmartLast, Heeluxe has built the FITGALAXIE database containing over 9,000 scientifically measured shoes. The data has become an invaluable resource for brands and retailers, helping them benchmark fit, analyse competitors and make data-led design decisions.

SmartLast has also driven a substantial reduction in fit inconsistency. Before its launch, Heeluxe’s human testing revealed variation of ½ to 1 full shoe size between models – even within the same brand. SmartLast’s sensor-based measurements reduced typical variation to between ¼ and ⅛ of a size. This has improved consistency, fit confidence and end-user comfort while boosting brand trust.

As Gray explains: “SmartLast allows brands to guarantee that a customer’s size will feel the same every time they buy, regardless of the shoe type.”

Continued collaboration

What began as a single sensor supply project has grown into a long-term innovation partnership between Heeluxe and PPS. “We’re both companies full of curious people,” Gray says. “As well as the PPS brings ideas, challenge us and help us push things further. That makes our products better.”

A joint roadmap is already in motion, including hardware upgrades to introduce factory-level fit tracking, integration of customer-feedback and online review data, and exploration of a Kids SmartLast system for youth footwear testing.

These ongoing developments reflect a partnership built on trust, where PPS’s reliability and technical precision continue to support Heeluxe’s mission to make the world’s shoes fit better.

“PPS became a valuable innovation partner,” concluded Gray. “Their reliability made it possible for us to help improve the footwear industry.”

To find out more about the applications compatible with PPS’s tactile sensors, visit its case studies on its website.