The 3D printing world is exploding, with researchers in fields across the spectrum drumming up formerly unthinkable projects. It was tough to narrow it down, but here are the five most fascinating 3D printing projects that are in the works: Swim like an octopus
Underwater divers may soon be able to swim like an octopus. Researchers in Germany have used 3D printers to build a propulsion system that mimics the unusual way that an octopus quickly flees an attacker. While an octopus normally makes its way along the ocean floor with its eight arms, when it needs to move fast, it uses a different technique. Head first, it sucks water into its body and then shoots it out behind it, pushing itself forward. It can control its path by altering the direction it shoots the water. Researchers at the Fraunhofer Institute for Manufacturing, Engineering and Automation built a system that similarly sucks water into balls and then pushes it back out. "Similar to the biological model – the octopus – the system can speed up a vessel really fast," said Andreas Fischer, one of the engineers on the project. In addition, the system is extremely quiet. Imitating an octopus is interesting enough, but to build the system, the researchers developed an efficient process using 3D printers. The design spits out semi-finished and complete components in the printing process for a dramatically reduced assembly process compared to typical motors, Fischer said. It also has fewer components. The system could also offer some environmental advantages over traditional motors. "In contrast to ship propellers, it is quiet and fish cannot get caught in it," Fischer said in a press release describing the system. He's not sure yet if the final product will be cheaper to produce than a standard motor but given the fewer components and simplified assembly, it might. The engineers think the design is well-suited for small boats, jet skis, or even surf boards. Initially, they are hoping to commercialize a "scooter" that pulls divers into deep water. So far the researchers have tested the system in a laboratory setting. Grow new bones
Kevin Shakesheff, a professor in the University of Nottingham's center for biomolecular sciences, has helped develop a way to use 3D printers to give a little boost to the body's natural ability to repair bone. Bone marrow contains a type of stem cell that forms new bone tissue when bone is injured. "We have this repair mechanism ready to go," Shakesheff said. The problem is it doesn't work when you've lost too much bone, for instance in an accident or if bone is lost to remove a tumor. His method starts with taking a 3D xray that shows the exact shape of the defect and becomes the basis for the shape printed by a 3D printer. The printed form contains both the patient's stem cells as well as a polymer material that adds strength. "The stem cells alone wouldn't have that strength. They need to work for many months to develop the tissue," he said. The polymer material is biodegrable and is naturally broken down by the body slowly, over about a three month period. "That's long enough for the stem cells to start to lay down their own bone matrix," he said. Shakesheff has assembled a multidisciplinary team capable of solving the range of technical problems that the project faced. For instance, regular 3D printers use very high temperatures when printing materials as hard as bone. But doing so would damage the stem cells that Shakesheff needed to use. "So we designed a process whereby you can bring very hard materials at temperatures at or below 37 Centigrade [98 degrees Fahrenheit]. That means you can do the whole process without using temperatures that can damage the cells," he said. He's proved that the process is safe in animal studies. The next step is to complete the approval process for human clinical trials. Shakesheff and his team showed off the process at the Royal Society Summer Science Exhibition in London and are completing a paper that they hope will be published. Eliminate the organ transplant waiting list
Sometimes it's the strangest things that inspire breakthroughs. For bioengineer Jordan Miller, the Bodies Exhibition and a dessert fad led to the development of a system that one day might be used to 3D print organs for people. Miller's research begins to solve one of a handful of problems facing scientists trying to build organs out of living cells. While scientists have been able to grow thin tissues like skin and a cornea from a patient's own cells, creating denser body parts like organs has been a challenge, Miller said. One approach has been to stack layers of cells to make something the size of an organ like a liver, but the cells in the center end up dying because they aren't being fed by a blood vessel system, like natural organs, he said. A light bulb went off for Miller, who was a post doc fellow at University of Pennsylvania, while visiting the Bodies exhibit. In one part of the exhibit, the artist displayed the blood vessel system by injecting silicon into the blood vessels and then dissolving away the rest of the surrounding tissue. Now an assistant professor at Rice University, Miller wondered if he could do essentially the opposite – create the blood vessel network in a substance that could be dissolved away to create channels for blood to flow. But what material to use? "We couldn't use the silicon or plastics the artist uses because you can dissolve them but any solvents you use would kill any cells you put around it," he said. A short time later Miller was eating dessert at a restaurant and saw a sugar cage, created when a chef drapes melted sugar onto a form like a bowl, later removing the bowl and leaving behind a cage-like structure made of sugar. Miller's team built their own 3D printer that prints out a structure made of sugar mimicking the blood vessel system. They then created a gel that contains living cells and poured it over the structure. Water in the gel slowly seeped into the sugar lattice, dissolving the sugar. Pumping out the sugar through the blood vessel network removed it, leaving behind a pathway for blood to travel and feed the surrounding cells. It's a breakthrough, but Miller stressed that the scientific community is quite far from actually making a functioning organ this way. No one yet knows how to make an organ that's life size or how to grow the type of cells that would be required. "This is not ready for human therapy yet but this was a big step for us in the lab," he said. Reduce the spread of disease in poor nations Many of the medical breakthroughs in 3D printing revolve around fixing a problem after it happens – like replacing a diseased kidney or repairing bone. But here's one that could prevent disease: a 3D printer project aimed at building composting toilets. A group of students from the University of Washington last year won a competition that awarded them $100,000 for their toilet printing idea. The concept is particularly novel because it uses plastic waste, like milk jugs, to build the toilets. The project is also unusual because it aims to build an object as large as a toilet. In order to create big objects, the students built their own printer, made from salvaged parts as well as parts that were created with a smaller 3D printer. The students proved that their printer could work and that using waste plastics was a viable concept last year when they designed and printed a boat and participated in a popular Seattle contest whose entrants race boats they build of milk cartons. The idea of using 3D printing to build toilets – objects that have well-established manufacturing process – may seem uninteresting. But in poor, developing nations the lack of toilets leads to many serious health problems. This project could reduce the cost of building and distributing toilets in those areas. The project is underway but Matt Rogge, one of the team members, declined to provide additional details about progress. He said that he and his partners may be headed in different directions but that they'll have more to share about their plans in the future. Innovate faster In an industry like satellite manufacturing, which may require unusual materials and demands only a relatively small number of final products, innovation is costly. One company might want to launch several dozen satellites a year. To keep costs down, the company will want to use a mass manufacturing process. "But the challenge is you are not launching the same satellite," said Amit Bandyopadhyay, a professor at Washington State University's School of Mechanical and Materials Engineering. Developers want to be able to try different designs, but crafting those parts using the traditional manufacturing process is time consuming and might not make sense due to the small number of pieces required. Bandyopadhyay and his colleague Susmita Bose, also a professor at the school, are working with Aerojet Corp. on using 3D printing to allow satellite designers to make modifications and then print out the new pieces. That would let the satellite engineers launch satellites with modified designs more quickly. "It adds a tremendous amount of flexibility to a designer's hand," Bandyopadhyay said. They are focusing for now just on the propulsion system; the rest of the satellite would be built using traditional manufacturing techniques. "We really focus on the key parts that are difficult to manufacture, that are the most time consuming," he said. The added challenge in satellite manufacturing is that some pieces of satellites must be crafted using materials like ceramics or titanium that can withstand high temperatures and that degrade slowly. Such materials are traditionally difficult to manufacture, he said. His team, which has been using 3D printing to build products using metals since 1995, works on commercial 3D printers. They're able to miniaturize pieces so that the final satellite is around the size of a coffee cup. Smaller satellites reduce the required fuel which in some cases means the satellite can carry additional instruments. His team hopes to have finished products ready to be launched in about a year. This is the only project he's aware of to use 3D printing to build satellite parts but it's not hard to imagine other fields that might benefit from a similar process.