Prof. Olaf Diegel has designed and built a variety of products: lighting equipment, home-health monitors, and even 3D-printed guitars .

Diegel, an instructor of Additive Manufacturing (AM) at the University of Auckland, is now creating technologies to help contain the spread of coronavirus and COVID-19, including face shields and a hands-free, foot-operated door opener.

The "foot opener" clips onto the bottom of the door and, if necessary, can be locked on and hand-tightened with two bolts.

Then, just step on it.

"I always believe that the simpler something is, the better it works," Diegel told Tech Briefs. "So, this one is about as simple as it gets."

Diegel's Creative Design and Additive Manufacturing Lab at the University of Auckland educates industry about how to properly use AM, in a way that adds enough value to overcome the otherwise high costs and slow speed of alternative manufacturing technologies.

a 3D-printed Spider guitar built by Prof. Olaf Diegel
Diegel's 3D-printed 'Spider' Guitar

Diegel, who has a background in product development, helps companies to redesign their products for AM, often by reducing the weight of parts.

"We can help them with their design whether it’s an existing product that needs updating, or a completely new idea that is still just a twinkle in their eye and walk them through the process of idea validation, detailed engineering design, manufacturing, and getting it out to market," said Diegel.

We spoke with Prof. Diegel about his recent inventions and advice he has for engineers with completely new ideas.

What role should 3D printing play in the creation of these kinds of protective medical products?

Prof. Olaf Diegel: If a part is not specifically designed for 3D printing then, chances are, that there are more cost-effective ways to make it. It’s also why I am not being obsessive about using 3D printing for personal protective equipment (PPE). If it can be done with a laser cutter instead, that tends to be a much faster and cost-effective method to make it. Only use 3D printing if it truly adds value to what you are doing.

photo of Prof Olaf Siegel from the University of Auckland
Olaf Diegel

In some cases 3D printing may add enough value to be worthwhile to make a single item for yourself, but not to make hundreds or thousands. In other cases, like the relatively complex venture PEEP valves used in ventilators, 3D printing may absolutely be the way to manufacture them.

And that’s probably the main advice I would give to engineers that are looking to design parts for 3D printing. Learn the basic design-for-additive-manufacturing rules: Things like minimizing the amount of material used, design to minimize post-processing, increase functionality by consolidating several parts into one or by making the component 90% lighter than the original one.

What inspired the creation of the hands-free door opener?

Prof. Diegel: The foot opener was mainly inspired by the need to avoid the transmission of COVID-19 through the hands which, I understand, are one of the most common ways these diseases are transmitted when the hands touch the face.

There have been quite a few open-source arm-based door openers popping up around the world, so I thought it might be good to have a foot-operated version for those who want to avoid the problem altogether.

I have also done an arm-operated one , which I have offered to print for anyone in New Zealand who needs it.

The products were designed for powder bed fusion 3D printing technologies (selective laser sintering ), as these are the technologies most suitable for producing large number of parts in a single print. They are printed in nylon. However, it would not be hard to modify the designs slightly to make them printable with extrusion technologies and desktop printers. The CAD models were put together so that they can almost instantly be modified to be adaptable for the many door handle shapes out there.

What other inventions are you working on to support coronavirus-response efforts?

Prof. Diegel: I am also working on a number of other PPE devices, focusing mostly on designing them so that they are efficient to manufacture in large quantities if needed.

There are plenty of open-source products out there now, but most are designed for making a one-off device for personal use (which is fantastic) but not for larger manufacturability. A screenshot of the face shield  I am working on right now is below. You’ll notice that the "frame" has been split in two to make it easy to nest them for laser cutting. This means that about 4 times more can be laser-cut out of a sheet than if it were a single piece.

a screenshot of a face shield design from Prof Olaf Diegel
Diegel's face-shield design. The frame is split in two for easier laser cutting.

I have also been putting together a small library of the many open-source COVID-19 designs (ventilators, PEEP valves, face masks and shields, swabs, etc.) that have been springing up all around the world, so that we have these on hand and can choose the most suitable ones for the New Zealand (or other country) context, modify them if needed, and then manufacture them as efficiently as possible.

a physical prototype of the PPE face shield from Olaf Diegel
A laser cut version of the face shield, laser-cut by Mike Carrigan of ITS LTD.

What innovative ideas have you seen to help address the coronavirus-response effort? Share your comments and questions below.