Two areas that are emerging in 3D printing are optics and nanoprinting. Companies such as LuXeXceL are pioneering 3D printing optically clear parts for LED arrays and other applications. Meanwhile Cytosurge and others are printing at the nanoscale. German company Nanoscribe has placed itself at the direct intersection of both these emerging trends by 3D printing optics at the nanoscale. Nanoprinting could have a considerable impact on many areas from medicine to electonics.
What is nanoprinting?
A nanometer is one billionth of a meter. Nanoscale fabrication (nanofabrication) is a series of technologies being developed to make structures and even machines ranging in size from about one to a hundred nanometers. Nanoprinting usually refers to 3D printing/additive manufacturing being used to build parts this size. Nanotechnology is any one of a series of technologies and operations done at this scale and is an emerging research area. To give you an idea of the sizes we’re talking about, “a sheet of paper is about 100,000 nanometers thick” and “One nanometer is about as long as your fingernail grows in one second.” Tiny is a word that doesn’t even cover it.
Nanoscribe started as a 2007 spin-off from the Karlsruhe Institute of Technology. The company is one of the leaders in nanofabrication. Nanoscribe’s 3D printers are used for biofabrication, optical interconnects, microfluidics, metamaterials, microrobotics and other applications. As well as being able to build and manipulate objects at the nanoscale it is widely thought that materials and processes can be manipulated and created in fundamentally new ways through nanofabrication. Much of the work being carried out at the moment is pure research in many different application areas, but this may be a development that could have profound applications across many industries.
Nano 3D Printers
The company deploys a number of technologies but its 3D printing technology works with galvanometers, lasers and photosensitive materials. It is very similar in a way to stereolithography. Imagine a Formlabs 3D printer, just much more expensive and able to produce much smaller things. Piezo-actuators are responsible for giving models Z (height), and X and Y motion come from the laser beam which is scanned and position by galvos. They call this moving-beam fixed-sample (MBFS) nanoprinting by two photon polymerization (2PP).
The video below shows you nanoprinting in action.
The Photonic Professional GT
The Photonic Professional GT is Nanoscribe’s commercially available nano-3D printer. It has a build volume of around 100 × 100 mm² and includes a microscope camera to check out your prints and software. The company’s DeScribe software imports and fixes STLs, slices and previews them. Their NanoWrite software lets you precisely tweak and control the printer. It has another element which could be much more broadly applied to other 3D printers: a self-leveling vibration isolation frame that could improve many existing 3D printers.
3D Printing of Micro-Optics
What Nanoscribe has now demonstrated is that University of Stuttgart researchers can use the technology to, in the course of one day, print a “directly 3D printed doublet lens systems onto CMOS image sensors thereby creating a high-performance and compact imaging system,” as the company explains. The system as is can serve as a powerful portend to what this technology can mean for cameras, lens systems and other electronics.
The company also showed that they can 3D print diffractive optical elements (DOE): “DOEs can be designed for functionalities that are hardly accessible with refractive optics, such as the generation of almost arbitrary light distributions in the far-field.”
The company also made hemispherical micro-lenses: “They have a shape accuracy better than 1 µm and a surface roughness better than 10 nm Ra. The array with a size of 1 square centimeter in total and semispheres with a height of 150 µm was written into a solid negative tone resist.”
Nanoscribe mainly sells to researchers now, who are using their technology in a myriad of ways. In 3D photonics, new structures and materials can be created; in 3D tissue engineering, structures such as bone could be replicated or augmented; in microfluidics, micro sized pumps could change how fluids move inside many application areas. Micromachines could bring any number of new developments which we can not even sufficiently contemplate now.
A video of helical micromachines moving around, made with a Nanoscribe 3D printer:
It is clear that Nanoscribe and the researchers working with their nanoscale 3D printers will continue to surprise us with their research. Whereas many 3D printing technologies produce very obvious and visible parts with immediate applications, nanoprinting is an area which we currently do not completely understand. There seem to be any number of near term applications which can influence wafers, semiconductors, electronics or medicine. How will manipulating materials at the nanoscale affect engineering, medicine and other areas? Will we be able to find new ways to engineer structures inside the body? How will nanosized machines be used? Nanofabrication is sufficiently complex and exciting that it almost seems to enter into sci-fi territory.
Eric Drexler has (much to his later dismay) publicized the concept of Grey Goo, a doomsday scenario whereby self-replicating nanomachines will end the world.
“Imagine such a replicator floating in a bottle of chemicals, making copies of itself…the first replicator assembles a copy in one thousand seconds, the two replicators then build two more in the next thousand seconds, the four build another four, and the eight build another eight. At the end of ten hours, there are not thirty-six new replicators, but over 68 billion. In less than a day, they would weigh a ton; in less than two days, they would outweigh the Earth; in another four hours, they would exceed the mass of the Sun and all the planets combined — if the bottle of chemicals hadn’t run dry long before.”
He goes on to say,
“Early assembler-based replicators could beat the most advanced modern organisms. ‘Plants’ with ‘leaves’ no more efficient than today’s solar cells could out-compete real plants, crowding the biosphere with an inedible foliage. Tough, omnivorous ‘bacteria’ could out-compete real bacteria: they could spread like blowing pollen, replicate swiftly, and reduce the biosphere to dust in a matter of days. Dangerous replicators could easily be too tough, small, and rapidly spreading to stop — at least if we made no preparation.”
Generally I believe that one of the main benefits of 3D printing as a technology is that it forces science fiction authors to think harder. Each day researchers in our field show up to work and after a full day can go home in the knowledge that somewhere hard at work there is a science fiction author that has to dream harder or create ever more terrifying dystopian nightmares in order to sufficiently keep pace with their research. The worlds of Neal Stephenson and others are being created during their lifetimes. Whereas Jules Verne died before perpetual submarines or space travel became a reality (and steam punk a fashion thing), today’s authors risk being overtaken by technology. We are often irrationally exuberant when we write about 3D printing. There was a time where everything we did was amazing and exciting and was going to change the world. We should generally be a bit more skeptical about the things that cross our desks. Many fanciful 3D printing companies and projects were clearly unrealistic from the get go. In nanofabrication, however, we find ourselves at a start of a new era in manufacturing. 3D printing in and of itself has much it can do in terms of gradient materials, metamaterials, form factor reduction, direct printing of electronics, weight saving, optimization of structures and the manufacturing of completely new things. Additionally nanoprinting can bring to humanity considerable benefits and risks. This is a Pandora’s box of a technology whose implications can not be foreseen. Watch this space because it will have profound implications for our collective future.