Glass 3D Printer by MIT: an exclusive interview with Dr Pierre-Thomas Brun

Posted By Sculpteo on Mar 16, 2016 | 0 comments

MIT hosts some of the most prolific labs when it comes to 3D printing! It excels in various fields such as design, materials or 3D printer. Dr. Pierre-Thomas Brun is a young French mathematician based at MIT and a member of the team that created the amazing molten glass 3D printer – which they call  “viscous sewing machine“. He kindly accepted to answer our questions.

Dr. Pierre-Thomas Brun is an Instructor in Applied Mathematics at MIT. Prior to joining MIT in 2014, he received his B.Sc and M.Sc from Ecole Polytechnique and Cambridge University, and his Ph.D. from Université Pierre et Marie Curie. He pursued his postdoctoral studies at EPFL, in Laboratory of Fluid Mechanics and Instabilities. On his blog – Science I do – this is how he presents his work:

“My research is concerned with the mathematics driving the world that surrounds us, from mundane situations such as the coil formed by honey falling onto a toast to the self-similar solution describing the curling of blood cells during egress of malaria parasites. I concentrate on studying the dynamics of fluids and flexible solids, with particular attention given to non-linear effects which I explore combining table sized experiments, precision numerics and theory. I strive to take the best out of these complementary tools to rationalize the physics underlying such systems. “

After a long discussion within the team Sculpteo, we focused our interest on 9 questions, which Pierre-Thomas very warmly agreed to answer. Here they are:

By perusing your previous work, our first question is: how do we go from the flow of honey on slice of bread to molten glass?

I’m currently working with Neri Oxman to the MIT who is a is a researcher/designer, very active in the world of 3D printing. Her team recently developed a 3D printer, then they called on to me to study the behavior of the molten glass. I was delighted to get down to a practical problem which allows making concrete objects (as opposed to the honey, that always ends up spreading out).

Is the process very unstable? E.g. Do we have to control the temperature to the nearest tenth of a degree?

Not at all and this is the advantage. These loops very typical of honey are so robust, we can even see this phenomenon with climbing ropes or cables. It is therefore no surprise when the same behavior is observed with glass, which is halfway between viscous and elastic material.

The FDM technology allows experimenting a large range of viscous materials. Do you think that other techniques could be used to 3D print with glass? We think more to the drop technology rather than the powder technology.

I don’t know, we go away from my area of expertise.

During a layer deposition, is the previous layer still viscous and is there a risk of collapsing? If the solidification of the previous layer already happened, won’t the final object be too fragile and highly anisotropic?

As soon as we want to create a 3D structure we have to deal this compromise which you perfectly brought forward. The temperature of the production batch is controlled in order to keep the deposed glass at a specific viscosity to avoid this issue.

What is the maximum size on the XY-plane we can print?

Typically around thirty centimeters, but we work on bigger.

Do your equations perfectly predict the shapes realized by the fluid whatever the characteristics of the deposited material are. Is there of the empirical?

There is almost none of the empirical. The model actually allows to avoid difficulties due to glass cooling and to predict the exact shape of the motives at the same time.

Do you think that spider may have an intuitive knowledge of these equations?

I don’t think so but there are some species in nature that use “unstable” processes to get by (locomotion, access to water or food, reproduction…) and not only spiders.

Crédit Photo: PT Brun

Our readers will probably have the same question, what would be the price for a prototype of your first machine?

 It is too early to say. The principal problem is still to have access to the molten glass…

Do you think that there is enough math in 3D-printing or would the engineer gain by working closer to mathematicians?

If you want to know more about 3D-printing with molten glass, we recommend this BBC report to you. You can also visit the personal website of Dr Pierre-Thomas Brun.

Until you can print (one day!) glass at Sculpteo, you can consult our list of incredible 3D-printed materials or download our ebook “The 3D Printing Material Bible“.

Pictures from PT Brun.