Robot chocolatier (RoboChocolatier) as a materials science teaching demo for autonomous science

[sgbaird]

Various conversations to be condensed.

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Thanks for starting this conversation. It sounds like a fun idea. My motivation for thinking about chocolate in this context comes from the attached paper that describes how chocolate can illustrate a lot of materials science relationships in terms of processing-structure-property relationships. Robert - it sounds like this concept is on your radar as well. I'd be curious to compare notes and perhaps land on a cool and tasty pedagogical tool/lab. An autonomous or automated system to study this, particularly if it could be put together cheaply, could be very interesting as well.

I've been poking around a bit. One option would be to connect a tempering machine to a chocolate 3D printer, crush the printed pieces, and have an option for recycling the chocolate back into the tempering machine.

I looked around at a bunch of chocolate 3D printers. ProCusini ($3700), Cocoa Press ($10k), and FoodBot ($2500) seem like reasonable options because they offer control of parameters like extrude temperature, print speed, and layer height. Cocoa Press is kind of in limbo for at least a year. There's also a printing attachment ($300) to existing 3D printers that sounds like it takes a lot more tinkering. MyCusini ($600) is there too, but it seems like parameter control is intentionally taken away from the user.

Also looked into the tempering machines. On the commercial side there's the Chocovision V ($2000). A KitchenAid with the "Precise Heat Mixing Bowl" seems like a good lower-cost option: https://www.youtube.com/watch?v=y-f4ynzAqe0. My wife was wondering why I was watching a cooking show, but it made sense once she saw it was about chocolate tempering.

What inputs do you think would be interesting to control and what outputs do you think would be interesting to measure? (These could be from the article that you attached)

Interesting teaching lesson from the American Ceramic Society: "TEACHER INSTRUCTIONS: How Strong is Your Chocolate?"

http://ceramics.org/wp-content/uploads/2014/04/How-Strong-is-your-Chocolate-Lesson.pdf

This lab is an interesting find. Sounds like a fun intro mechanics lab. Certainly hanging pennies is easier than finding an instron.

The kitchen equipment you found seems interesting, unfortunately it all comes with a several k$ price tag and does not really address the question of how the samples would be moved around and tested. 3D printing could be a nice path to sample preparation, but we might also get by doing something much simpler.

We have a senior design competition in which groups of MechE seniors work together to design and prototype a product. It might be that something can be pieced together from inexpensive bits to comprise sample processing and testing.

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Akshually…
A robot chocolatier would be the perfect analog of a robot metallurgist. Fine chocolate is all about heat treatment. There is a famous MRS symposium back in the 2000s on the metallurgy of chocolate.

The flavor and texture of chocolate is all about phase transformations, grain growth etc.

Chocolate is tempered and the finest chocolate is attained by ensuring super fine grain structures

Correction:
The name if the symposium was “the materials science of chocolate” and there were several papers on the processing and microstructure of chocolate. It was very very interesting!

Anyways, I think this would be a great idea!

1. Chocolate making has to go through a liquid phase
2. Chocolate does not make sense in thin films. It is a bulk material
3. There are lots of things you can do on the chemistry side to change properties
4. There is perhaps a lot more to do on the processing side
5. Testing chocolate = Tasting chocolate, which is really nice

It will be really exciting to see what can be done in this space

Thanks for the patience as I'm looping back to this. This is great feedback and thanks for the great resource! The alignment with a robot metallurgist is a big appeal to me. I also like the contrast between thin films and bulk materials. I do wonder what the search space would look like (starting materials, processing conditions).

A couple related resources for chocolate metallurgy:

• https://www.ijee.ie/articles/Vol22-5/03_ijee1826.pdf
• http://ceramics.org/wp-content/uploads/2014/04/How-Strong-is-your-Chocolate-Lesson.pdf

I just put out a more fleshed-out idea for a solid-mixing demo using colored wax powder. Curious to hear your thoughts! https://www.linkedin.com/feed/update/urn:li:activity:7037877617215107072/

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Is the Cocoa Press 3D Chocolate Printer "hackable"? I'm considering using it in a closed-loop fashion, but would need to be able to remotely control variables such as extrude temperature and climate. I wouldn't fit into the profile of most customers, as I'd be looking to use this to benchmark optimization algorithms and looking at it from more of a research/scientific perspective (e.g. mechanical properties of the chocolate) rather than a more typical perspective prioritizing taste, texture, and looks.

Thanks! I appreciate the reply and info. The prototype looks nice! A year might be too long, but then again it seems like a lot of the other products out there aren't quite as tunable as what you described. If it's the difference between spending a ton more time forcing hackability on a different system or using something that's more amenable to that out of the box, a year+ wait might be worth it.

Are you targeting a similar price point (~$10k) for the new machine?

Also, I've appreciated the Cocoa Press blog posts! Great for someone new to chocolate-making and interested in some of the science and behind-the-scenes. In particular, it was nice to see the reference to one of the tempering machines, and it's been getting me thinking about how I could have a tempering machine as part of the closed-loop process. Some of the scientific interest there is that it introduces temperature and mixing speed each as a function of time as a preprocessing step.

Are you aware of any other chocolate 3D printing machines that might have that control of temperature, print speed, etc.? FoodBot got back to me and mentioned that the temperature can be adjusted on the screen, the layer height via Cura, but that the print speed is essentially fixed. Pro/My/Cusini got back to me saying that there's no control of the parameters.

Whoops I forgot to add cost info. We are aiming for a sub $2,000 price point for a kit version. I really want to get this thing into the hands of a lot more people! Yeah, some of the other food printers are lacking. One additional benefit we have over them is the ability to adjust temperature in 0.1 degree increments instead of 1 degree increments (C).

I appreciate the compliments on the blog! I passed on your comments to Amy, the material scientist who wrote those :-)

The other printer to check out is: https://chocolate3.de/chocolatehoch3-individual-chocolate-with-3d-printers/. If you reach out, tell them Cocoa Press sent you! We're friends. That being said, I have no idea if they have printers in stock to ship, or where they are at the moment. It's been on my list to reach out to them this week.

You could reach out to https://www.3dbyflow.com/ as well (also tell them Cocoa Press sent you if you do!). They have a super impressive looking chocolate printer but have been extremely tight-lipped about any specifics. It has a built in tempering though which is super interesting!

I don't want to talk negatively about any other companies, but these are the only other companies that I think could potentially fit the bill.

Anyway, I'm just really interested in your research and would love to stay in touch whether or not you end up using our machine.