Sleek computers and thin, powerful phones are perhaps the most recognisable result, but other sectors are going through the same process and having even greater impacts on people’s everyday lives. Smaller biomedical devices – such as hearing aids and implantable medical tools – can be utterly transformative for users.
American firm Boston Micro Fabrication (BMF) aims to meet growing demand for miniaturised parts with a manufacturing technology that might not have seemed suitable even a few years ago.
“When the parts are very, very small, there haven't historically been 3D printers able to do things at that scale,” says CEO John Kawola, speaking to Professional Engineering ahead of his 22 July session at the free Engineering Futures webinar series. “One of the workarounds was just ‘Make it bigger.’”
Such a simple trick might work for prototyping, but it is out of the question when pursuing production volumes of smaller and more efficient devices.
Now there are printers to meet that need, however. BMF is one of several companies releasing ultra-high resolution 3D printers aimed at production quality printing of tiny parts. The MicroArch S240, for example, offers printing resolution of down to 2μm (microns) while working with photosensitive resin ceramic.
BMF 3D printers use a variant of stereolithography, in which layers of resin are cured by a light source. Unlike other technologies, which use lasers, the BMF approach uses digital light processing (DLP) projectors – hence it is often called DLP 3D printing. The technique offers very high resolution, with surface finishes of 1μm and below.
Unlike other DLP methods, BMF printers are top down, reducing the number of printing supports that are needed. The small parts’ low mass also prevents the need for some supports.
Overcoming hurdles
Thanks in part to supply chain disruption, another trend alongside miniaturisation is a growing movement towards 3D printing for large scale manufacturing.
“3D printing is being considered across lots of different industries – whether it's plastic or metal parts, small parts – as an alternative, primarily because you don't have the traditional set-up and tooling costs,” says Kawola.
“Let's say for example I'm making plastic parts. You normally have to make an injection mould. Well, that injection mould costs tens of thousands of dollars or more, it may take six weeks, eight weeks, 12 weeks to get it.”
He adds: “At the micro scale, that's magnified even more, because the tool… is often much more expensive. So instead of being $20- or $30,000, it might be $200,000. So there's even more of a benefit to be able to think about alternative ways of manufacturing.”
John Kawola will be speaking at the free Engineering Futures webinar series
That shift means a change in focus when designing parts and products, Kawola says. ‘Manufacturability’ was the conventional hurdle, but modern 3D printing techniques and materials can tick the strength, longevity and safety boxes.
3D printing also removes many of the limits imposed by conventional techniques. “Geometric freedom” lets manufacturers make parts lighter or stronger, Kawola says, or focus on specific aspects of the eventual product – such as a drug delivery device that delivers medication inside the body as efficiently as possible.
The second major hurdle for manufacturers and product designers is the economics. 3D printing probably does not make economic sense if you are making millions of parts, for example.
“It's driven by a couple of things, and one is the speed of the process. Injection moulding, once you're all set up – even though you may have to wait 10, 12, 15 weeks to get the mould and it's expensive – is very fast. You're moulding a part every one, or two, or five seconds. It's pretty quick.
“3D printing, in general, is not nearly that fast. And then there's just the cost of the equipment, cost of the 3D printing materials.”
If you are making thousands or tens of thousands of parts, however, Kawola says the technique is “pretty attractive” and he is “absolutely” confident that larger-scale 3D printing will become more economical in the coming years.
“Over the last 10 years cost has come down, machine throughput has gone up, materials are getting better and better. So I think all those things are happening to try to get 3D printing to the place where, let's say, moulding or machining is in terms of economic viability.”
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.