Fabbing tools in orbit and with memory materials, and new structural configurations of DNA.

Dec 24, 2014

A couple of weeks ago before Windbringer's untimely hardware failure I did an article about NASA installing a 3D printer on board the International Space Station and running some test prints on it to see how well additive manufacturing, or stacking successive layers of feedstock atop one another to build up a more complex structure would work in a microgravity environment. The answer is "quite well," incidentally. Well enough, in fact, to solve the problem of not having the right tools on hand. Let me explain.

In low earth orbit if you don't have the right equipment - a hard drive, replacement parts, or something as simple as a hand tool - it can be months until the next resupply mission arrives and brings with it what you need. That could be merely inconvenient or it could be catastrophic, situation depending. Not too long ago Barry Wilmore, one of the astronauts on board the current ISS mission mentioned that the ISS needed a socket wrench to carry out some tasks on board the station. Word was passed along to Made In Space, the California company which designed and manufactured the 3D printer installed on board the ISS. So, they designed a working socket wrench using CAD software groundside, converted the model into greyprints compatible with the 3D printer's software, and e-mailed them to Wilmore aboard the ISS. Wilmore ran the greyprints through the ISS' 3D printer. End result: A working socket wrench that was used to fix stuff in low earth orbit. One small step for 3D printing, one giant leap for on-demand microfacture.

In other 3D printing news, we now have a new kind of feedstock that can be used to fabricate objects. In addition to ABS and PLA plastics for home printers, and any number of alloys used for industrial direct metal laser-sintered fabbers there is something that we could carefully count as the first memory material suitable for additive manufacture. Kai Parthy, who has invented nearly a dozen and counting different kinds of feedstock for 3D printers has announced his latest invention, a viscoelastic memory foam. Called Layfoam and derived from his line of PORO-LAY plastics, you can run Layfoam through a 'printer per usual, but after it sets you can soak the object in water for a couple of days and it becomes pliable like rubber without losing much of its structural integrity. This widens the field of things that could potentially be fabbed, including devices for relieving mechanical strain (like washers and vibration dampening struts), custom padding and cushioning components, protective cases, and if bio-neutral analogues are discovered in the future possibly even soft medical implants of the sort that are manufactured out of silicone now.

In the early 20th century the helical structure of deoxyribonucleic acid, the massive molecule which encodes genomes was discovered in vivo. While there are other conformations of DNA that have been observed in the wild only a small number of them are actually encountered in any forms of life. Its data storage and error correction properties aside, one of the most marvelous things about DNA is that it's virtually self-assembling. A couple of weeks ago a research team at MIT published a paper entitled Lattice-Free Prediction of Three Dimensional Structures of Programmed DNA Assemblies in the peer reviewed journal Nature Communications. The research team developed an algorithm into which they can input a set of arbitrary parameters like molecular weights, atomic substitutions, microstructural configurations, and it'll calculate what shape the DNA will take on under those conditions. Woven disks. Baskets. Convex and concave dishes. Even, judging by some of the images generated by the research team, components of more complex self-assembling geometric objects could be synthesized (or would that be fabricated?) at the nanometer scale. Applications for such unusual DNA structures remain open: I think there is going to be a period of "What's this good for?" experimentation, just as there was for virtual reality and later augmented reality, but it seems safe to say that most of them will be biotech-related. Perhaps custom protein synthesis and in vivo gengineering will be involved, or perhaps some other applications will be devised a little farther down the line.

The best thing? They're going to publish the source code for the algorithm under an open source license so we all get to play with it.

Welcome to the future.