3DPrinting Body Organs >

Circulatory System

Circulatory System (Photo credit: kevin813)


The goal of building lab-grown bodily organs out of a patient’s own cells is something that Bio-engineers have been advancing toward, but a few major challenges remain – one of them is making vasculature, the blood vessel plumbing system that delivers nutrients and removes waste from the cells on the inside of a mass of tissue.

Without these blood vessels, interior cells suffocate and die.

Growing thin layers of cells is already possible, so one proposed solution is to “print” the cells layer by layer, leaving openings for blood vessels as necessary. The downside is that this method leaves seams in the printed output: when blood is pumped through the vessels, the seams are pushed apart.

The University of Pennsylvania’s Bio-engineers have turned the problem inside out by utilising a RepRap 3DPrinter called to manufacture templates of blood vessel networks out of sugar. Once the networks are encased in a block of cells, the sugar can be dissolved, leaving a functional vascular network behind.

“I got the first hint of this solution when I visited a Body Worlds exhibit, where you can see plastic casts of free-standing, whole organ vasculature,” says Bioengineering postdoc Jordan Miller.

Miller, along with Christopher Chen, the Skirkanich Professor of Innovation in the Department of Bioengineering, other members of Chen’s lab, and colleagues from MIT, set out to show that this method of developing sugar vascular networks helps keep interior cells alive and functioning.

After the researchers design the network architecture on a computer, they feed the design to the RepRap. The printer begins building the walls of a stabilizing mold. Then it then draws filaments across the mold, pulling the sugar at different speeds to achieve the desired thickness of what will become the blood vessels.

“I got the first hint of this solution when I visited a Body Worlds exhibit, where you can see plastic casts of free-standing, whole organ vasculature,” says Bioengineering postdoc Jordan Miller.

When the sugar becomes hardened, the researchers add liver cells, suspended in a gel, to the mold. The gel surrounds the filaments, encasing the blood vessel template.

After the gel sets it can be removed from the mold with the template still inside. The block of gel is then washed in water, dissolving the remaining sugar inside – the liquid sugar then empties from the vessels it has created without harming the growing cells.

“This new technology, from the cell’s perspective, makes tissue formation a gentle and quick journey,” says Chen.

The researchers have successfully pumped nutrient-rich media, even blood, through these gels blocks’ vascular systems. They also have experimentally shown that more of the liver cells survive and produce more metabolites in gels that have these networks.

The RepRap makes testing new vascular architectures quick and inexpensive, and the sugar is stable enough to ship the finished networks to labs that don’t have 3DPrinters of their own. The researchers hope to eventually use this method to make implantable organs for animal studies.

 Video by Kurtis Sensenig

Materials: Wood Filament > > > 
The End of Opensource? > > >
3 Colour Home 3DPrinting > > > 

3DPrinted Gun Pt4: What Now? >

Click the image to view the full Stratasys letter to Defense Distributed

In a now ongoing saga Defense Distributed, a group of pro-gun lobbyists with the idea to 3DPrint a live firearm, has had its 3DPrinter seized by the machine’s manufacturer Stratasys.

Comments on the Wiki Weapons story so far have condemned the notion of a 3DPrinted gun – one that would enable anyone, anywhere, to manufacture their own weapon – with negative feedback, and now congratulatory remarks applauding Stratasys. Stratasys informed develop3d.com of their official line on the episode:

“Stratasys reserves the right to reject an order. Members of Defense Distributed, like any U.S. citizens, are able to follow the well-established federal and state regulations to manufacture, distribute or procure a firearm in [the U.S.A.].”

Matter resolved? Responsible company stepping in and doing the safe, legal and proper deed, it could perhaps be concluded as such. But, for example, a 3DPrinting professional visiting a school in South London, U.K., to show students 3DPrinting asked them what they could imagine printing for themselves… a student replied:


Whilst some students may be intrigued by innovative cutlery design, and schoolboy bravado regarding an interest in weapons/ fast cars/ protein suppliments, we will inevitably face the forthcoming legislative backlash regarding the concern that if anyone can download a file to manufacture a weapon, and the technology continues to progress, ‘press to print products’ will degrade into a home 3DPrinting black market.

How to stop 3DPrinted home weaponary proliferation? Restricting C.A.D. files of weapons from appearing online seems to obvious and popular suggestion – although this simply leads to the difficultly in policing the internet.

The limitations of most available 3DPrinters, materials and processes, mean an readily accessible 3DPrinted threat to humanity is certainly not here yet: but as the inevitability of the wave of concern now seems set, so does the non-rhetorical that 3DPrint makers, bloggers and journalists need to pose to their audience:


“What should we do about this?”


3DPrinted Gun Pt1: Control Debate >
3DPrinted Gun Pt2: Campaign Stopped >
3DPrinted Gun Pt3: Seized >
3DPrinted Gun Pt4: What Now? >




Over the past week the 3DPrinting community has felt the emerging impact of what could be a full evolutionary shift, a divisive decision, or a simple misinterpretation of far from simple legal jargon…


The name ‘MakerBot’ is currently synonymous with 3DPrinter as much as ”RepRap.’ If neither of these names are of significance to the reader as yet, that would suggest that the reader is currently dipping their toe into the pleasantly warm waters of the world’s most hyped emerging technology – most hyped outside of a certain company who would doubtless craft an ‘iMaker’ or ‘iBot’ if it were swimming here too… As the iPhone 5 release was attracting attention on the level we are now accustomed,  MakerBot released the second version of their flagship Replicator 3DPrinter and the Twitter fraternity drown in a flood of #Replicator2 hashtags in due response.
What MakerBot also did was have to blog a response to a back lash of suggestions that they have stolen many tens of thousands of user created, opensource, 3DPrintable designs of ‘things’ (products) on their free hosting site Thingiverse.com. This accompanied concern that their new design steps away from the revolutionary OpenSourcenature of home 3DPrinters that have evolved from RepRap designs back in 2008.These vital and very interesting issues have been emerging for some time now, pretty much as long as 3DPrinting has been attracting hype on a massive level.____________________________________________________________________

The timeline of apparent events:

  1. July 2010 – RepRap blog posting about the heated conveyor belt
  2. August 2011 – Makerbot Industries receives $10M venture capital funding. Applied for patent on heated conveyor belt.
  3. November 2011 – Makerbot Industries filed for a patent on a heated conveyor belt.
  4. February 2012 – New Terms Of Service on Thingiverse
  5. Thingiverse blog post about the TOS – only one commenter, “madscifi,” asked about the 3.2 attribution clause but wasn’t answered.
  6. July 2012 – Makerbot gets the patent. Their own design is highly flawed and no longer included in the next 2 generations
  7. September 2012 – Replicator II announced as a closed source design. 
  8. September 2012 – Blog posting about the Replicator II being closed source, later added TOS change by Josef Prusa (Twitter)
  9. Included “.thing” file format just a .zip of printable .stl and .obj files.
  10. “Occupy Thingiverse Test cube” posted on Thingiverse, more attention to TOS
  11. Josef Prusa Google+ posting
  12. Tony Buser (Makerbot Industries) posting on Google+ that the TOS didn’t chance in 8 month. 
  13. Thingiverse amke a blog post, clarifying that the TOS change was in February 
  14. Brainstorms appear regarding creating new alternatives to Thingiverse. (Thingiverse2Githubconverter, SKDB)
  15. More “occupy Thingiverse” objects popping up all the time.
  16. The story got slashdottet
  17. Blog posting by Makerbot Industries- They are “working out” just how open source they can make the Replicator II, lots about their intentions, no clear work about the specific TOS sentence. It looks like at least the software is just a thin, closed source UI that calls open source Skeinforge or their new (open source) “Miracle-Grue“.
  18. As a response the blog post by Josef Prusa gets updated. 
  19. Thingiverse replacement taking some shape in the comments of a G+ posting.
  20. Reaction of HoekenHackadayHacker News report on the issue, audience attention exponential – reports appear to suggest that the new closed-source software can be tricked into working with older MBI printer.
The change in the Terms of Serice appears to be as followoing – previously they had a paragraph: “Thingiverse.com does not claim ownership of the materials you post, upload, input or submit to the Thingiverse.com site.”The current TOS states a lot of granted rights but they are all limited to: “solely for the purposes of including your User Content in the Site and Services”.
What is interesting is the next sentence: “You agree to irrevocably waive (and cause to be  waived) any claims and assertions of moral rights or attribution with respect to your User Content.”
There appears to be no reference to this made in the february blog posting about the Terms Of Service. The recent blog posting reassures us that attribution is done, but still doesn’t explain why the user has to agree with this when uploading a design.Moral rights in the US are separate from copyright and thus not affected by Creative Commons – but why would one waive any but the “right to the integrity of the work”? A read of the definition over at Wikipedia tells us that the move could actually be a good thing, Thingiverse may be attempting to cover the backs of their users, and themselves, as much as possible:
“Moral rights are rights of creators of copyrighted works generally recognized in civil law jurisdictions and, to a lesser extent, in some common law jurisdictions. They include the right of attribution, the right to have a work published anonymously or pseudonymously, and the right to the integrity of the work.
The preserving of the integrity of the work bars the work from alteration, distortion, or mutilation. Anything else that may detract from the artist’s relationship with the work even after it leaves the artist’s possession or ownership may bring these moral rights into play.Moral rights are distinct from any economic rights tied to copyrights. Even if an artist has assigned his or her copyright rights to a work to a third party, he or she still maintains the moral rights to the work.”
The latest MBI blog posting states that they are working out “how open source” they can make the Replicator 2. What has currently not been clarified is the Thingiverse TOS sentence about waiving attribution…


Here is the response to this development by Zaxhary Smith, one of the Founders of MakerBot and a big name in the 3DPrinting sector:

My name is Zachary Smith, aka Hoeken.I have been building 3D printers since 2007 as part of the RepRap project. I created a non-profit foundation (the RRRF) dedicated to pushing open source 3D printing forward. In 2009, I invited my friends Adam Mayer and Bre Pettis to go into business with me building 3D printers.Thus, MakerBot Industries was born.Fast forward to April, 2012 when I was forced out of the very same company. As a result, I have zero transparency into the internal workings of the company that I founded. See this article by Chris Thompson for more infomation.I do not support any move that restricts the open nature of the MakerBot hardware, electronics, software, firmware, or other open projects. MakerBot was built on a foundation of open hardware projects such as RepRap and Arduino, as well as using many open software projects for development of our own software.

I have been withholding judgement until hearing official word regarding the open source nature of the latest MakerBot printer. I’m trying to contact people to find out what the real scoop is but so far nobody is talking, and my ex-partners are not returning phone calls or emails. It certainly doesn’t look good.

Not only would it be a loss of a large Open Hardware manufacturer, but it would also be a loss of a poster child for the movement. Many people have pointed at MakerBot and said “Yes, OSHW is viable as a business model, look at how successful MakerBot is.” If they close those doors, then it would give people who would say OSHW is not sustainable ammunition for their arguments. It would also discourage new OSHW companies from forming. That is a sad thing indeed.

For me, personally, I look at a move to closed source as the ultimate betrayal. When I was forced out, it was a normal, if unfortunate, clash of wills where one person must stay and one person must go.

I swallowed my ego and left, because I knew that the company I founded would carry my ideals further into the world.

Regardless of our differences, I had assumed that Bre would continue to follow the principles that we founded the company on, and the same principles that played a major part in the success of our company.

Moving from an open model to a closed model is contrary to everything that I stand for, and as a co-founder of MakerBot Industries, it makes me ashamed to have my name associated with it.

Bre Pettis, please prove me wrong by clarifying exactly what license MakerBot will be releasing the design files and software under.  That is all we (the community) wants.

In closing, I would like to point out the Open Source Hardware Definition




Open source hardware is hardware whose design is made publicly available so that anyone can study, modify, distribute, make, and sell the design or hardware based on that design.

The hardware’s source, the design from which it is made, is available in the preferred format for making modifications to it.

Ideally, open source hardware uses readily-available components and materials, standard processes, open infrastructure, unrestricted content, and open-source design tools to maximize the ability of individuals to make and use hardware.

Open source hardware gives people the freedom to control their technology while sharing knowledge and encouraging commerce through the open exchange of designs.’




Is the MakerBot Replicator 2 Open Source?

‘We’re working that out and we are going to be as open as we possibly can while building a sustainable business. We are going to continue to respect licenses and continue to contribute to the open technology of 3D printing, some of which we initiated. We don’t want to abuse the goodwill and support of our community. We love what we do, we love sharing, and we love what our community creates. I believe strongly that businesses that share will be the winners of tomorrow and I don’t think that’s a secret. Even companies like Google and IBM are embracing open source and finding new ways to share these days.

I’m looking forward to having conversations with folks at the Open Hardware Summit to talk about how MakerBot can share as much as possible, support it’s 150 employees with jobs, make awesome hardware, and be sustainable. Will we have to experiment to make this happen? Yes, and it’s going to take a lot of collaboration, cooperation, and understanding.

I wish there were more examples of large, successful open hardware companies.

From a business perspective, we’ve been absurdly open, more open than any other business I know. There are no models or companies that I know of that have more than 150 employees that are more open. (Would love to be wrong, but I don’t think I am.) We are experimenting so that we can be as open as possible and still have a business at the end of the day.

Will we be successful? I hope so, but even if we are not, everyone will find out that either being as open as possible is a good thing for business or that nobody should do it, or something in between. I personally hope that we succeed, not just because I love what people make with MakerBots and I love the employees that make these machines but because I believe that MakerBot as a business can create a new model for businesses to learn from.

I don’t plan on letting the vulnerabilities of being open hardware destroy what we’ve created.’

Did Thingiverse terms of use change to “steal” people’s things.

Thingiverse does not steal.

We created Thingiverse to be the greatest place to share things using open licenses.

The terms, that we set up in February of this year, allow us to share your designs on our website and protect us from companies with lawyers.

Could we make that more user friendly? Yes, but lawyers cost money and making it simple for people to understand will cost many hours of lawyer time.

I’ve put it on our todo list for 2013 to make the terms easier to understand and avoid misunderstandings. If you’re concerned about this make sure to read the post that I wrote earlier this year about the terms of use on Thingiverse.’




Visualising Data Using a 3DPrinter > > >


‘Some time ago, I had some data that lent themselves to a 3D surface plot. The problem was, the plot was quite asymmetrical, and finding the right viewing angle to see it effectively on a computer screen was extremely difficult. I spent ages tweaking angles and every possible view seemed to involve an unacceptable compromise.

Of course, displaying fundamentally 3D items in two dimensions is an ancient problem, as any cartographer will tell you. That night, as I lay thinking in bed, a solution presented itself… I had recently been reading about the work of a fellow University of Bath researcher, Adrian Bowyer, and his RepRap project, to produce an open-source 3DPrinter.

The solution was obvious: I had to find a way to print R data on one of these printers!

I managed to meet up with Adrian back in May 2012, and he explained to me the structure of the STL (stereolithography) files commonly used for three-dimensional printing. These describe an object as a large series of triangles. I decided I’d have a go at writing R code to produce valid STL files.

I’m normally a terrible hacker when it comes to programming; I usually storm in and try to make things work as quickly as possible then fix all the mistakes later. This time, I was much more methodical. As a little lesson to us all, the methodical approach worked: I had the core code producing valid STL files in under 3 hours.

Unfortunately, it then took until September 2012 before I could get hold of somebody with a 3DPrinter who’d let me test my code. A few days ago the first prototype was produced:


So now I’d like to share the code under a Creative Commons BY-NC-SA licence, in case anybody else finds it useful. You can download the code here, in a file called r2stl.r.

One day, when I learn how, I might try to make this a library, but for now you can just call this code with R’s source()command. All that is in the file is the function r2stl(), and having once called the file withsource(), you can then use the r2stl function to generate your STL files. The command is:

r2stl(x, y, z, filename='3d-R-object.stl', object.name='r2stl-object', z.expand=FALSE, min.height=0.008, show.persp=FALSE, strict.stl=FALSE)

    • xy and z should be vectors of numbers, exactly as with R’s normal persp() plot. x and y represent a flat grid and z represents heights above this grid.
    • filename is  self-explanitory.
    • object.name The STL file format requires the object that is being described to have a name specified inside the file. It’s unlikely anybody will ever see this, so there’s probably no point changing it from the default.
    • z.expand By default, r2stl() normalizes each axis so it runs from 0 to 1 (this is an attempt to give you an object that is agnostic with regard to how large it will eventually be printed). Normally, the code then rescales the z axis back down so its proportions relative to x and y are what they were originally. If, for some reason, you want your 3D plot to touch all six faces of the imaginary cube that surrounds it, set this parameter to TRUE.
    • min.height Your printed model would fall apart if some parts of it had z values of zero, as this would mean zero material is laid down in those parts of the plot. This parameter therefore provides a minimum height for the printed material. The default of 0.008 ensures that, when printed, no part of your object is thinner than around 0.5 mm, assuming that it is printed inside a 60 mm x 60 mm x 60 mm cube. Recall that the z axis gets scaled from 0 to 1. If you are printing a 60mm-tall object then a z-value of 1 represents 60mm. The formula is min.height=min.mm/overall.mm, so if we want a minimum printed thickness of 0.5mm and the overall height of your object will be 60mm, 0.5/60 = 0.008, which is the default. If you want the same minimum printed thickness of 0.5mm but want to print your object to 100mm, this parameter would be set to 0.5/100 = 0.005
    • show.persp Do you want to see a persp() plot of this object on your screen as the STL is being generated? Default is FALSE.
    • strict.stl To make files smaller, this code cheats and simply describes the entire rectangular base of your object as two huge triangles. This seems to work fine for printing, but isn’t strictly proper STL format. Set this to TRUE if you want the base of your object described as a large number of triangles and don’t mind larger files.

To view and test your STL files before you print them, you can use various programs. I have had good experiences with the free, opensource Meshlab.

Even if all you ever do is show people your 3D plots using Meshlab, I believe r2stl() still offers a useful service, as it makes viewing data far more interactive than static persp() plots.



# Let’s do the classic persp() demo plot, as shown in the photograph above

x <- seq(-10, 10, length= 100)

y <- x

f <- function(x,y) { r <- sqrt(x^2+y^2); 10 * sin(r)/r }

z <- outer(x, y, f)

z[is.na(z)] <- 1

r2stl(x, y, z, filename=”lovelyfunction.stl”, show.persp=TRUE)

# Now let’s look at R’s Volcano data

z <- volcano

x <- 1:dim(volcano)[1]

y <- 1:dim(volcano)[2]

r2stl(x, y, z, filename=”volcano.stl”, show.persp=TRUE)

I hope you might find this code useful. ‘

– Ian Walker, Department of Psychology, University of Bath.