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Although often perceived as buzzwords used to create excitement around a product, 3D printing and nanotechnology are two relatively new fields that are being used in combination to create a wide range of interesting new technologies. Here we will talk about what these two disciplines are, and how they’re changing things up.
Traditional manufacture usually takes place as a ‘top-down’ approach. This is where a material is removed until only the final form is left, such as carving a sculpture from a block of marble, or cutting out a shape from a sheet of metal. This process can be wasteful as a lot of the time the excess material isn’t recycled. Additive manufacture is the opposite of this procedure, known as ‘bottom-up’, with the component being built piece-by-piece or layer-by-layer, until it is fully formed. 3D printing falls under the description of additive manufacture and uses a moving head to deposit a layer of material, which is then moved up or down and a new layer is then built on top of the previous one with another pass of the printer head. The slices are built up like this and it is possible to fabricate complex structures with precise measurements. 3D printing can be used with polymers, plastics and ceramics to produce components that may not have been possible using conventional manufacturing techniques.
The original idea behind nanotechnology came from a talk by famous physicist Richard Feynmann entitled “There’s Plenty of Room at the Bottom”, where he described scientists in the future manipulating individual atoms and molecules to create new materials that make use of effects only seen at that size scale. In the nearly 60 years since this lecture, nanotechnology research is pursued worldwide and brought about some significant scientific advancements. While there are a few definitions of the word, we will use NASA’s which says it is “the creation of functional materials, devices and systems through control of matter on the nanometer length scale (1-100 nanometers), and exploitation of novel phenomena and properties (physical, chemical, biological, mechanical, electrical...) at that length scale.” Nanotechnologies can be manmade like carbon nanotubes for filtration, or naturally occurring such as the tiny hairs on geckos feet that allow them to cling to walls.
By combining these two disciplines there is the capacity to make huge changes to how existing components are produced, as well as creating completely new materials, with applications from semiconductor electronics to medicine. Nanotechnology stands to benefit from 3D printing as it allows the materials and devices to be assembled without a human operator. This would speed up previously lengthy tasks, produce less waste, and because it is automated these processes can become economically viable. This viability is the key to taking these technologies out of the lab and into places where they can make a real difference.
One example of a 3D printing being used as a nanotechnology is a process known as two-photon lithography. This is similar to traditional stereo-lithography but the laser-cured resin can absorb two photons at once. This only happens where the laser has enough intensity, which is right at the center, and therefore allows much greater precision in the curing process. The technique can achieve resolutions of less than 50 nm, allowing structures such as castles to be built on the head of a pencil. A Vienna based team hopes to use this technique along with a biocompatible resin to make support scaffolds for living cells.
It isn’t just the medical field that is making use of 3D printing and nanotechnology; it can be used for developing new, high strength materials for building as well. A team out Virginia Tech in the United States is engineering nanoscale features into 3D printed materials that give existing materials previously impossible mechanical properties such as minimal weight and maximum strength. They design the materials from the nano through to the micro to the macroscale so that the properties may be retained and made use of. These properties can be strength, hardness, or even an increase in the tensile elasticity, all of which may be of use to the aerospace and defense sectors.
These are just two small examples of where 3D printing is being used to create nano-sized structures or features in materials. 3D printing offers a great improvement in the speed at which these materials can be produced, which has been a significant hurdle to their more widespread introduction. With interest continuing to grow into this field, technologies such as these may be closer than previously thought.
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