It could be a marriage made in engineering heaven: Additive manufacturing and nanotechnology. First, let’s introduce additive manufacturing. Throughout history manufacturing of metallic parts and most other materials as well starts with a solid shape of the material and gets cut down to size. If you want to make a sword, you first get a longish, thickish rod or plate of metal and then start cutting, filing, heating, banging, grinding, and honing until it finally looks and works like a sword. In short, the traditional process mostly involves subtracting material. Additive manufacturing, as the name implies, goes about it from the other direction, it adds material. The idea’s not new, but the ability to create things by a carefully controlled addition of many layers has become practical only within the last decade or two.
Perhaps the best known example of the additive process is the Hewlett-Packard 3-D printer, or as it is now called: Designjet 3D. Announced in January of 2010 to considerable hoopla, it’s just now coming to market at the popular price of about $17,000 (which is actually a lot cheaper than heavy-duty commercial versions of similar technology). It uses a thermoplastic (ABS) as the construction material and as controlled by a computer with Computer Assisted Design (CAD) software, it can create objects by spraying layer after layer of the plastic to build up a complete shape. Its immediate use is for prototyping designs. The idea sounds neat, if somewhat like science fiction. However, the fact is additive layer manufacturing (ALM or often just AM) has many forms and is slowly but surely becoming a factor in the world of commercial manufacturing.
The reasons for the rise in popularity start with economics: There is much less waste. On average, about 26 times less waste of material than standard manufacturing. This is related to a second big reason for popularity: The high degree of control over the process. By constructing things layer by layer to very exact specifications, components can be built that are impossible with traditional methods. This leads to a third reason for popularity: Designers and engineers are freer to use their imagination. After all, additive layer manufacturing’s first tasks were to make prototypes. AM is very good at making one-of-a-kind pieces, for example, artificial hip joints for specific people. All this control and freedom does have a drawback, AM processes are not very robust, that is the precision required is difficult to maintain. The mechanics are finicky and difficult to calibrate. The hard part for using AM on commercial quantity production for standard metallic or plastic components is the need to make it less delicate.
With nanotechnology, however, working with extreme precision at very small scale is the name of the game. Nanomanufacturing is already built on the foundation of very complex and ‘delicate’ machinery – marrying it with additive layer manufacturing at its present level of sophistication seems like a natural fit.
Researchers are working at combining high-performance polymers (such as polyether ether ketone, or PEEK) with carbon nanotubes. The hope is to develop AM ‘printing’ techniques that combine growing carbon nanotubes within the material in aligned formation. In short, the goal is to embed the carbon nanotube structures to perform electronic functions such as sensing and communications. Most AM techniques involve the spraying or deposition of very fine-grain particles, which are then burned or manipulated with high-powered lasers, so it’s no surprise AM companies are working with makers of nanoparticles to experiment with improved composite construction, or to add electrical properties.
The combination of additive manufacturing and nanotechnology falls into the domain of ‘emerging technologies.’ There is a perceived need to provide manufacturing techniques for some kinds of nanotechnology that are between the self-assembly envisioned at the molecular level and the traditional techniques applied to micron (or larger) scale materials. As far back as 2004 (practically ancient history in the nanotech business), a conference on Advanced Technology and the Future of American Technology came to the conclusion:Highly miniaturized, functional, and efficient electronics devices, and precise and selective biomolecular materials are part of this future. At the same time, it is not yet well known how to manufacture nanomaterials and how to integrate nano- and large-scale manufacturing. Advancing these developments depends on the ability to foster multidisciplinary interconnections between researchers in a range of scientific and engineering disciplines, business managers, policy makers, and educators.
[Source: Georgia Tech]
What is called for could be the use of nanoparticles within the composites of additive manufacturing.
For more background on additive manufacturing, I’d recommend The rise of additive manufacturing at the Engineer (UK).