Scientists infused a 3D-printed rabbit with genetic material, the first step toward a potential “DNA of things” where biology makes gadgets smarter.
For the last nine months, Yaniv Erlich has carried a small, white, plastic rabbit wherever he goes—to work at Israel-based DNA testing company MyHeritage, to scientific conferences, through airports, and across international borders. The kumquat-sized bunny, cute as it may be, isn’t a toy or a good luck charm. But if you cut off its foot, something miraculous might happen. From that severed piece, you could make more rabbits just like it, provided you had a DNA sequencer and a 3D printer.
Allow me to explain. DNA is nature’s information storage medium—the same molecules in one configuration make a banana, arranged in a different sequence they make a 720-sexed slime mold. But it’s just code. Which means you can store other stuff in it too. Scientists, including Erlich, have been doing this for a while now. Multiple companies are pursuing DNA data storage too. But no one had yet taken advantage of the fact that DNA is so small and information-dense, it can be woven into the fabric of everyday objects. Do that, says Erlich, and you can start to create a “DNA of things,” a collection of gadgets made smart not by their ability to talk to each other over radio waves, but by the information infused into the material of the gadgets themselves.
That’s where the bunny comes in.
It was 3D-printed in Switzerland, in the lab of Erlich’s ETH Zürich collaborator, Robert Grass. Embedded in the figurine’s polymer matrix are trillions of microscopic glass beads, each one enclosing a few dozen molecules of synthetic DNA. Encoded into this DNA is the digital blueprint for the bunny itself, the instructions that tell a 3D printer nozzle where to move and when to squeeze to make its four paws, two ears, and cottontail. Altogether, the bunny contains 370 million copies of the data file that describes its contours, a data file well-known to computer graphics and industrial design nerds the world over.
This blueprint goes all the way back to the spring of 1993, when a Stanford Graphics Lab post-doc returned from a shopping trip with a terracotta rabbit. Using the lab’s laser scanners and rudimentary image-stitching software, he built a computerized version of the clay statue. The Stanford Bunny, as it came to be known, was one of the first digital representations of a 3D object.
The bunny became a training ground for a generation of computer graphics designers. They learned how to layer textures and render fur over its leporine curves. It was smashed and fractured and melted in service of advancing their animation skills. It became so iconic that to this day, almost anyone learning to use a 3D printer starts out by making a plastic version of the same rabbit.
So in a way, Erlich’s bunny is the ultimate inside joke. “Plus, you know, you pull rabbits out of the hat,” he says. A computational biologist-slash-white-hat hacker, Erlich gained notoriety in the mid-2000s for using a well-placed cell phone to break into a major Israeli bank. A few years later, he unmasked the identities of people listed in an anonymous genetic database, using only an internet connection. Then, last year, he showed that such databases have grown so big, it’s now possible to find more than half the US population, even people who’ve never taken a DNA test.
He first hatched the idea for DNA-infused objects with his brother in-law, a graphic designer. They were talking about how to make photos—real ones, the kind you put in frames and albums—hold up over time. It made him think: Maybe it would be possible to convert a jpeg file into DNA and spray it on the photo itself, a finishing step to give it digital replicability.
But DNA is a fragile molecule. High temperatures, strong pH swings, and UV light all cause it to deteriorate, degrading the information it encodes. Preserving its chemical structure is key to any DNA data storage dreams.
Erlich emailed Grass, the guy who’d pioneered a method to trap DNA molecules inside a tiny protective glass shell. In 2013, he had figured out how to create silica particles with a positive electrical charge, making them stick to negatively charged DNA. They’d form a thin film that could protect the molecule from a number of threats.
Using that technology, the pair designed a process for producing materials with their own DNA memory, just like the cells in your own body. It involves first converting the digital blueprint of an object into a genetic sequence, producing the corresponding molecules of DNA, encasing them in silica, embedding the beads in melted plastic, spinning that plastic into filaments, loading those filaments into a 3D printer and then printing the object. Easy! They describe the work in today’s issue of Nature Biotechnology.
Just as it’s theoretically possible to take a few cells from your body and make another copy of you as a clone, you can snip a little piece off Erlich’s rabbit and use it to make others. The one he carries around, in fact, is a third-generation clone. The data file Grass’s team used to 3D-print it was retrieved from a tiny piece of ear from a bunny that had come from a tiny piece of an ear of the first bunny they made. They dissolved away the plastic and glass from the ear fragment, converted the remaining DNA back into a digital file, and uploaded the file to a 3D printer. All together, the scientists made five generations of bunnies with no information loss between manufacturing cycles. The bunnies, and the digital files that described them, remained identical over many months.
“This is a very initial foray into one of the more promising applications of DNA data storage: ubiquitous storage,” says Sriram Kosuri, a biochemist at UCLA who was not involved in the work. With ubiquitous storage, all everyday objects could be tagged with useful information, such as where they were manufactured, their ingredients or composition, instruction manuals, safety warnings, and recommendations for how best to recycle or dispose of the item. “What’s cool about this work is they show that it is doable today, and it seems pretty reliable,” says Kosuri.
Sure, it’s doable. But practical? Not yet—not until DNA sequencers and synthesizers become cheaper and more commonplace. That doesn’t daunt Erlich, who has heralded the idea of ubiquitous sequencing enabling DNA-aware homes—faucets that test for harmful pathogens and toilets that report back on the health of their users’ gut microbiome. Why not appliances that are themselves made smarter through DNA?
“Embedding information directly into materials would actually be a really useful thing to do,” says Microsoft senior scientist Karin Strauss, who leads research on molecular information systems and has worked with DARPA to build an image search engine out of DNA. QR codes can wear off. User manuals disappear. URLs change. DNA-based information that’s physically built into an object could offer more permanence.
The technology still needs to be tested over longer periods of time, though, and under a variety of environmental conditions, like high heat and intense radiation, to see how well the embedded messages hold up. Researchers will also need to try out other materials and manufacturing processes.
Erlich’s team did report running an additional experiment—embedding a 1.4 megabyte video in a plexiglass pair of eyeglasses. It demonstrated not only the ability to store more data, but the potential to conceal such information. A DNA-of-things architecture could camouflage sensitive files in innocuous objects, turning them into secret storage devices capable of passing through security without detection. “The object will look just like an ordinary object, so it’s a very effective way of hiding information,” says Erlich. (Airport security and customs officials have yet to flag his rabbit.)
Grass, a chemical engineer, sees the technology’s most immediate promise in embedding information in long-lived objects that might outlast the company that produced them, and is mulling the idea of starting a new company that could commercialize this technology. Haelixa, a startup he cofounded in 2012, already sells silica-encased DNA barcodes that help track products through convoluted supply chains.
Meanwhile, Erlich, who conducted the research without grants or support from MyHeritage, will keep toting his bunny around as a prop to show off the promise of the DNA-of-things. Or maybe just as an opening to say that “reproducing like rabbits” might mean something radically different in Erlich’s version of the future. Every joke, after all, needs its punchline.
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