What if that same grace could be brought to manufacturing? That is the aim of Stilfold, a Swedish company that has developed an industrial origami manufacturing technology. Using bespoke software and a novel combination of hardware, the technique creates simple, smooth metal components that are much less ornate than their paper equivalents, but which offer manufacturers several potential advantages.
Chief amongst these is the chance to cut waste from manufacturing. By folding along curved lines, the process – which has received patents in Europe and the US – is designed to make the most of the simple starting materials. The result, according to Stilfold, is weight reductions of up to 40%, an up to 70% reduction in required components and up to 20% lower material costs. By lowering the energy required, it could also enable a massive 75% reduction in carbon dioxide emissions.
While those figures represent the best possible scenario, savings of any kind could be appealing for a wide range of industries. Based near Stockholm, Stilfold says its technology could be well-suited for automotive applications, aerospace, energy, and sustainable construction. Recent projects have included a research collaboration with Volvo exploring the Stilfold technique as an alternative to stamping and welding, an AI-enhanced lightweight drone design, and a scooter concept.
We spoke to engineering origami experts about the advantages and challenges involved with such a process, and where it could be best applied.
Into the fold
Similar ideas for manufacturing have been investigated since at least the 1980s, said Dr Mark Schenk to Professional Engineering, but “the challenge was actually doing the folding”.
Now Stilfold has developed and patented robotic folding methods, one of the main constraints is the dexterity of the tools. “You and I have very, very dexterous fingers to be able to do the fold, whereas reproducing that is hard,” said Dr Schenk, who did his PhD on origami and now works on morphing deployable structures at the Bristol Composites Institute.
“If you want to make the same part over and over again, you can create moulds and the like to do that. I think what they're trying to do is have a slightly more general-purpose manufacturing method.”
The computer process needed to design the fold has been another challenge, especially working with curved lines. “If you take a flat piece of paper or sheet metal, you draw a single fold on it, you've got almost an infinity of solutions, infinity of options,” Dr Schenk said.
“When you bend something it just prefers some configurations over others, but there's a huge freedom there… how you can describe the possible geometries is quite tricky. So I think what they've been working with is a design tool where you can explore the possible shapes you can generate.”
By creating 3D shapes that fold along curved lines, Stilfold says its Stilware software can allow designers to optimise designs for strength, material use and sustainability. That design is then handed to a system of robotically controlled rollers and tools.
A key part of deploying folded components will be the ability to analyse built forms, Dr Schenk said. “You can create quite complex 3D shapes, but there's a reason why many things that we design are straight lines. They're easier to calculate, easier to analyse, understand. So you need to be able to take these geometries, be confident you can make them, but also understand the structural performance.”
While folding should require less energy than deep drawing, for example, Dr Schenk said the new technique would be best suited for small-scale production, as the cost of tooling becomes less important when there are tens of thousands of parts to make. Automotive manufacturing could nonetheless be one of the most promising sectors for adoption, he said – while it is unlikely to replace manufacturing of the body work, it could be suited for individual components, bumpers or crash boxes that absorb energy during impact.
The technique requires a complete ground-up design process, he continued, which adds some constraints, but also new options. Companies might choose to press a shape, for example, before doing final touches with the Stilfold technique.
“It is impressive,” he said. “It is genuinely hard to make these things from sheet metal – again because it requires dexterity.”
He added: “It doesn't replace existing manufacturing, it offers an alternative, but you have to design with that process in mind… that’s the trade-off.”
Complex creativity
Stilfold is far from the only engineering operation exploring the use of origami. Dozens of research projects have investigated its adoption in everything from DNA nanotechnology to biomedical sensors, while origami-like techniques are being used in the design of deployable structures for satellites and spacecraft.
“Origami unlocks two basic aspects of mechanical and engineering research. One of them is shape and the other is mechanics,” said Dr Marcelo Dias, reader at the University of Edinburgh. “One of the reasons why origami is so fascinating is that you take a material which is a flat sheet, and by locally manipulating the folds you can generate a three-dimensional shape that is extremely complex, and the level of complexity is down to how creative you can be with the arrangements of folds.
“But it's known to be a very interesting mathematical problem for computation as well, because how many shapes can you get given certain constraints and rules of folding? It turns out that this is a computationally very challenging problem.”
The “secret” for Stilfold is more than the idea, he said, but it is the ability to tell a robot how to fold the designs, with curved lines bringing more complexity and creating shapes that are not possible with straight lines, including ones that can approximate smooth surfaces with fewer folds.
“The mechanics that you impart from this curved fold origami allows you to have structures that are very simple but extremely rigid,” said Dr Dias, who received his PhD in curved fold origami and problems related to the elasticity of thin sheets. One well-known example is boxes used to serve chips at McDonald’s, he said, which use folding tabs for shape and rigidity.
The durability of folded parts will need to be monitored, he added. “These structures are going to be out in the market, subjected to whatever environmental stress conditions that they have to [face]. And every time you add a fold, you add a weak point in the material.”
Such a bold new technique might bring new considerations – but as tariffs, net zero goals, electricity prices and other factors put pressure on companies around the world, many businesses might be keen to explore it.
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.