Brief Overview of Micro- to Nanoscale 3D Printing By Carrie Wong
Introduction It has been 30 years since Engines of Creation: The Coming Era of Nanotechnology was published by Eric Drexler. This book, written by an accomplished cryonics supporter, helped popularize the potential of molecular nanotechnology in the ’70s and ’80s. Thirty years ago, he described how microscopic robots could manipulate matter on a molecular level. This captured the imagination of many scientists around the world. In the beginning there were only a few visionaries who believed that something like this might be possible. Nowadays, scientists all over the world are developing ways to manipulate matter on smaller and smaller scales. Amazing technologies are being developed today, including nanoscale 3D printing. Cryonicists often get asked how they would come back and how the damage would be repaired in the future. In my experience, we mostly rely on some sort of “handwaving” explanation about how there could be future technology to bring us back. We often reference advances in nanotechnology to repair the damage of vitrification and what caused our critical condition in the first place. The skeptic often interprets this explanation as a deus ex machina with little basis. The majority of cryonicists are not experts in nanotechnology or 3D printing but we keep up with the headlines and these advances often sound promising. More often than not, cryonicists pay closer attention to 24
scientific advances than the general public. We often do have an edge when attempting to explain how exactly we would be revived in the future. In this article, I expand on modern research in nanoscale technology and 3D printing. Nanoscale 3D Printing 3D printing is also known as additive manufacturing. In basic terms, this technology often starts with a computerized 3D model, followed by an automated “build up” process that creates the object in 3 dimensions using layers or piece by piece. The 3D printer acts like a personalized manufacturing robot. This technology exploded in popularity in the last few years and the term “3D printing” is used to describe a plethora of new technologies. In 2012, researchers at the Vienna University of Technology broke the speed record for fabricating microscopic objects using a technique called “two-photon lithography”1. With lasers, they printed a high-resolution miniature Cathedral using resin that spanned 50µm in just a few minutes. In this new technique, the resin contains special molecules which are activated by the laser light and induce a chain reaction that causes the resin to turn solid. The resin only hardens when it absorbs two photons of the laser beam at once, which only occurs at the center of the laser beam1. This two-photon technique allows for precision and control of which parts of the resin harden. Solid material Cryonics / July-August 2016
Figure 1: Microscopic miniature cathedral. Credit: Vienna University of Technology
can be created anywhere within the liquid resin rather on top of the previous created layer only. Just this year, researchers at ETH Zurich published a new nanoscale 3D printing technique with metal materials2. This method is based on the FluidFM system developed at ETH Zurich several years earlier. With this technique, scientists were able to produce individual 3D metal pixels ranging in diameter from 800nm to 5µm. Using these metal pixels, they were able to build larger and mechanically stable, solid 3D objects. Impressively, they did all this without using any structural templates. In this system, there is a moveable micropipette mounted on a spring that can be positioned precisely2. A droplet is placed on a base plate made of gold, then the tip of the micropipette penetrates the droplet and acts as a print head. A copper sulphate solution flows through the pipette www.alcor.org