
Printing with sound - rbanffy
https://www.seas.harvard.edu/news/2018/08/printing-with-sound
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gene-h
TL;DR they make a droplet on a capillary tip and use the radiation pressure of
sound to push it off, enabling printing with liquids with viscosities ranging
over four orders of magnitude.

It's cool, but in the current approach they still need to produce a somewhat
spherical droplet in order to apply downward radiation pressure from sound. So
it would be hard to apply to printing of thermoplastics which might be more
prone to forming tubes rather than droplets. The fact that they need a 3d
droplet is another thing that will make scaling this approach interesting.
Because we need a somewhat complicated 3d structure, which is a capillary tip
inside a tube which needs to be longer than the droplet by some factor due to
the wavelength of sound, this is going to be challenging to fabricate in bulk
at the microscale like we do with today's inkjets. One might even need fairly
exotic processes like LIGA to fabricate structures with this aspect ratio.[0]

It may not end up being a mainstream droplet jetting technique, but the fact
they can jet liquids over four orders of magnitude is pretty compelling.
Especially for research purposes

Also, the materials and methods is somewhat entertaining. It's not often that
you see white chocolate, which they used as a substrate to print honey
droplets on to, listed as a material used. Tuning the parameters was probably
pretty tasty

[0][https://en.wikipedia.org/wiki/LIGA](https://en.wikipedia.org/wiki/LIGA)

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javiramos
You can print droplets of thermoplastics via the Arburg process [0].

[0] [https://www.arburg.com/en/products-and-services/additive-
man...](https://www.arburg.com/en/products-and-services/additive-
manufacturing/apf-process/)

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phonz
Doesn’t this have profound implications for 3D printing?

