Cohesion3D MicroFactory: Electronics Inside Plastic

Hello everyone,
I'm Ray from Cohesion3D. I'm working on a machine that can print any model using UV-cured resin and then print a circuit inside it with conductive inks. I've worked with circuitry since I was very young but I've actually never had a circuit board manufactured because it requires either toxic chemicals or costly and time consuming fab houses. Even though services like OSHPark have made this cost quite small, there's still a waiting period and pressure to get it right the first time, which can be detrimental to a healthy design cycle. I like how 3D printing lets me produce a design very soon after having an idea, without having to iterate tens if not hundreds of times before being able to justify the expense of having it manufactured. Being able to hold a working part right away gets the creative juices flowing and improves productivity, and I want to extend this ease of use to electronics prototyping as well.

Cohesion is a whole new way to prototype and manufacture hardware products as there is no circuit board at all. You just designate a cavity inside any CAD model and add your circuit board design there. At it's core, the Cohesion3D Microfactory is a multi paste extruder, so just slice the model as you normally would for a dual extruder print and go. It's still up to the user to place the electronic components by hand, as adding pick and place functionality would increase the complexity many times and add hundreds upon hundreds of dollars to the cost of each unit.

This is going to be an extremely easy to assembly kit. I've built other printers from kits before and have experienced the frustration of trying to line things up, having to measure, and perhaps worst of all, having to guess. I've addresed the weaknesses of 10 other printers I've seen in detail, as well as combined their strengths as I designed Cohesion. Assembling the frame is as simple as snap together and tighten some screws, and the toolheads are modular and interchangeable, which means you'll be able to add functionality such as a filament extruder, several different kinds and sizes of syringe and pump systems, and a lot more by simply snapping a module onto the carriage.


I really am trying to make this the best printer you can buy at the really low price point of $1199 considering all the functionality and customization it will offer. I'm planning to launch a crowdfunding campaign early 2015. I would be extremely grateful for any suggestions, complaints about your existing printers that I can avoid with mine, and questions that I can answer.
Please check out cohesion3d.com and tell me what you all think!

It sounds interesting, but how do you get reliable connections to the electronic components?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

dc42 - it's as simple as placing the components onto the printed traces right after they have been deposited, while the conductive ink is still wet. As it dries, it will hold the components securely. That's true for surface mount components. For thru hole, you can integrate the holes for the legs right into the plastic model under the circuit and this will provide additional holding strength.

Thanks for your interest!

Surface mount is fine for me. What is the conductive ink made of, and what is its resistivity? Most of my designs use a 2 layer board with vias, where the bottom layer is mostly a ground plane. Would I be able to replicate this? I'm wondering whether this could be a way of making prototype pcbs.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Since the core of the unit is a variety of paste extruder configurations, any number of inks can be used. Anything you can squeeze out of a syringe is applicable here.

I have a few inks in mind that I'll be experimenting with these next few weeks.

Bare conductive - this is a very thick and viscous paste with high resistivity. It's the cheapest out of all of them though, which makes it great for learning with. I also have some interesting applications for it that I'll share with you shortly.

There's an ink I'm about to test out which is fundamentally similar to bare conductive but has a much lower resistance (the vendor claims only 11 ohms/ sq while bare conductive claims 55 ohms/ sq). This ink is great for general use circuits and is what I plan to offer as standard. It's a water based ink made from graphite/ graphene.

For use cases where you need minimal resistance throughout, silver ink will be the way to go. MG Chemicals Silver Print claims less than 0.066 ohms/ sq to quote their site. This is mostly certainly on par with conventional PCBs.



As far as multi-layer boards - it can be done, definitely, but there's no concept of "upside down" when it comes to additive manufacturing. If you want to embed multi layer circuit designs inside a plastic part, just stack them and use the conductive ink to run wires between them for vias.

If you just want to prototype PCBs, as you said, you'd essentially need to print a plastic floor, then your ground plane/ bottom layer onto it, then the main plastic body, then the top layer. Or you could do the top and bottom separately, each with a plastic body, and join them together with pegs, screws, or glue and manually do the vias. I wouldn't want to do that though. Let me know if option 1 seems feasible.

Thanks

just saw this:
[www.kickstarter.com]

Is "normal" Filament and they claim to get 1ohm/cm,..