3D Printing and Grey Goo

3D Print of 3D Impression Scan

3D printing is the process of building tangible objects in a bottom-up fashion. Bit by bit. This can be seen as the reciprocate to conventional manufacturing processes, such as lath and mill, which remove material in a top-down fashion in order to achieve a desired shape.

3D printing is said to be a revolution in manufacturing. Actually this is just the beginning…

Building 3D from 2D

The concept, the idea was most inspiring. 3D Printing presented designers with a new level of freedom. Any 3D shape could be seen as 1D building blocks or 2D layers or cut through profiles stacked onto one an other like Lego. The stack of 2D layers represented that 3D shape. This formed the basis of modern 3D Printing.

Additive manufacturing, rapid prototyping or 3D printing as it is popularly referred to these days is not something new. The concept  is actually very old. But the most recent milestone was about 25 years ago with the mainstream introduction of several supporting technologies such as the PC. These technologies allowed 3D Printing to finally gain traction for a wide audience.

While there were several different 3D Printing technologies available at that time it was the SLA (Stereo-lithography) process that really broke new ground regarding the awareness of 3D print technologies.

One small, but important, highlight which made an impression on many people was when the SLA process was shown on the popular BBC program called “Tomorrows World” which aired early 1994.

During those days 3D printing was referred to as Rapid Prototyping since the printed products were considered to be Props and not real products. This was due to the typically weak and brittle properties of the materials used at that time.

The SLA process was patented in the late 80′s and was based on the use of photo-polymers. Laser light which was directed via controlled mirrors was used to cure the photo-resin in very localized and specific areas. A 2D sliced layer of an object was produced after each iteration onto which  the next 2D layer was built upon until the final shape was achieved. Other approaches were also presented such as using a mask to project the entire 2D slice each iteration. This resulted in higher printing speeds.

After that, many different types of 3D printing technologies started to gain popularity such as LOM, FDM and SLS. Development was progressing.

Most 3D print technologies revolved around the use of plastic or paper. But metals and even ceramics were being introduced as well. Even ice was experimented with using a TED (Thermo Electric Device). The TED was used to control the temperature of a support plate onto which small droplets of water were frozen onto to build an object.

Materials such as water and paper are inexpensive The byproduct is easy to handle and non-toxic. Photo-resins, however, were difficult to handle, had expiration dates and they are usually toxic. These limitations still apply today.

In any case it was clear that RP, or 3D Printing as we now call it, was revolutionary and would have a profound impact on many industries. For instance, in the early 90′s I wrote a letter to one of the most prestigious medical centers in the US. What I stated is that it might just be a feasible idea to 3D print a bio-degradable material to serve as a matrix for the culturing of bone cartilage.

By printing a matrix you could intrinsically control the shape in order to control factors such as how the cartilage will grow into the matrix. The cartilage would be that of the host so it would not be rejected by the immune system of the host. In others words you could build a process to build organic material in most any shape. Yes, a gruesome articulation. But think of the revolutionary possibilities in the area of prosthetic’s. Think of how many people it would help.

A lot of  R&D is being conducted on suitable matrix materials (a friend of mine recently made advancements in this area and now holds several patents and has received a new research grant). Here is one of the latest developments of another research.

Unfortunately this video is no longer available. However, It can still be found here.

Development of 3D printing technologies was not confined to just one nation or institution. Many institutions around the world were getting involved, in particular, in Israel, The United States and in Leuven Belgium there was a lot of activity already early on. They had the right mindset and clearly understood the value of these technologies.

Many people, including myself, followed and experimented with these technologies. A good reference that appeared about a decade ago about the various 3D print technologies can be found here. The links are probably outdated but it’s still a very valid overview.

That’s the past. But what about now?

3D Printing has now become mainstream regarding its concept and value. Most people are now aware of it and what it can do. In particular, the FDM process receives widespread application and development for home and small business use. This is due to its relatively low-cost, simple design and the easy handling of the base material being printed.

But probably the most effective way to 3D print with the greatest level of freedom is through 3D print service providers (3D-PSP). You get the widest possible choice of technologies and there is no cost of ownership pertaining to a particular machine.

A very long-standing 3D print service provider is Materialise in Leuven Belgium and not far from there is another company in Eindhoven the Netherlands that has gained a lot of attention called Shapeways.

“Listening is Perceiving, Seeing is Believing but Touching is Experiencing”

Rumor Control

3D printing progressively gains popularity. But it seems that the “hype factor” leads to many expectations which exceed the current possibilities of these technologies. Sure, today’s 3D printing technologies are going to make an impression in many areas of manufacturing and expand possibilities. But most all of the conventional manufacturing processes will simply co-exist. They will not be displaced just yet. Why? 3D printers can print the material and the required shape but there is a lot more involved in manufacturing products. Take for example the age-old fastening nail. This simple product is easy to print out, even in metal. But try actually using one to nail something together.  In most cases the nail will simply break into pieces the first time you hammer it down. Nails fasteners produced through traditional means are cold-drawn which raises their elastic limit and makes them stronger. The result? The nail has more tendency to bend back after a hard slam.

Don’t get me wrong. 3D printing already opens up many new possibilities and will continue to do so. But its important to know that most products have many different properties which must be met in order to serve as useful products. 3D printing planes, trains and automobiles? Well…not just yet.

The Future?

As indicated, 3D printing is still actually in its very early infancy. Despite many advancements on the market. Understanding this and the incredible future of these technologies means going back to the past again.

In the late 50′s a physicist by the name of Richard Feynman gave a lecture titled “There’s Plenty of Room at the Bottom” which posed the idea of being able to manipulate individual molecules and atoms. This lecture is considered by many to be the spark in the development of nano-technology. Technologies that relate to manipulating things at a molecular and atomic level, the building blocks of matter .

Years later Dr. Eric Drexler presented the book “Engines of Creation” in which he described the concept of self-replicating nano machines. He referred to a Grey-Goo which consisted of billions upon billions of these self replicating building machines. Molecule sized machines capable of building just about anything out of any material with near atom precision. 3D printing at a whole new level (see: Foresight Institute). Movies also appeared about the topic in the early 90’s. See, for instance, Deep Red and The Outer Limits episode The New Breed.

This future is still a long way off. But elements that are leading to it are slowly within our grasp. Nanotechnology actually already exists. Life itself is a product of nanotechnology. Its natures own secret technology.

As such, this brings forward some important questions that will need answers. The ability to manipulate things at a molecular level is of great concern to many scientists regarding its use and, in particular, its abuse. Great responsibility is needed for such a fundamental technology to co-exist with life as we know it. Its liberating, yet, frightening as well.

In the Ridley Scott movie Blade Runner a future is presented in which humans have reached a level of technological sophistication that they are able to create life in their own image. The question arises; are they also able to take responsibility for that creation? And, what if the creation seeks the creator for more?

Today we are already able to build basic micro sized machinery, view large molecules as well as 3D print structures at the nano level (see, for instance, the company Molecular Imprints). Of the many publications available on this topic probably one of the most interesting and practical information can be found in the book “Microstereolithography” regarding 3D MEMS production technology. Many different micro and nano type 3D Print approaches are presented.

But the prelude to pave the way to true nanotechnology development is probably “printing logic”. While additive manufacturing is great for printing tangible “mechanical” objects the concept is actually much broader in terms of its application. In the simplest sense Printing Logic reefers to printing PCB’s (Printed Circuit Boards). But its much deeper than that. Traditional PCB production and even photo-lithography processes rely heavily on a top-down manufacturing approach in which material is selectively removed. Additive PCB manufacturing opens up entirely new ways to produce PCB’s. You are building things bottom-up. In particular the popular applications are building onto flexible substrates. Think of a flexible screen. A great overview regarding these technologies can be found in this slide show from PARC.

3D printing is an exciting new field within manufacturing. It also presents one of the first milestones towards the development of the ultimate manufacturing process in which most anything can be produced. You could say that we used to 3D print “piece by piece” and now “bit by bit” and in the proposed idea of the future it will be “molecule by molecule” and even “atom by atom”.

“Hey…Is that Real or 3D Printed? What’s the difference?”[B.J. Rao]


Personal: Multi-cultural background. Professional: Technology and Business. Activities and Interests: Business, Philosophy, Culture, Technology, Projects, Passions

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2 comments on “3D Printing and Grey Goo
  1. Cabbage Stack says:

    My Interest is in 3D printing with casting or machinable wax or the like. This resolves a fairly hard problem of creating the wax patterns for investment casting down to one step. The 3D print goes directly from the printer right into the investment. I would have thought this would have been developed much earlier for that very reason. Apparently from what I’ve read it only been in the last 4 or 5 years that we have been seeing this. It has been done with PLA for quite some time, but with mixed results, as I understand it

    • B. J. Rao says:

      Hi, Back in the early 90’s my intent was to build a LOM based 3D printer. This approach uses sheets of paper cut into the desired cross-sections and stacked with an adhesive. The excess is removed and the 3D shape is revealed. A great setup was the Japanese KIRA LOM system. But instead of paper sheets I wanted to use polystyrene sheets. The idea being to create polystyrene patterns in a lost-wax investment casting system. Polystyrene can be a great replacement for wax in investment casting. In addition I contacted John Hopkins around 1992 with the idea to use porous sheets of bio receptacle material to create a 3D shapes and then use this as a matrix or lattice to culture bone cartilage for prosthetic use and maybe even the growing of blood vessels and some organs. But that is another topic. Btw, I never got a response from John Hopkins. Regards, B.J. Rao