3D Printing Tech Digest - May 2017

Feely bots a possibility

Researchers at the University of Minnesota have developed a method for 3D printing stretchable electronic sensors that could give robots the ability to feel their environment. They used a 3D printer (built in house and featuring four nozzles) to print different inks: a base layer of silicon ink, top and bottom electrode inks and a coil shaped pressure sensor, and a final layer that holds the top layer in place while it sets. These sensors set at room temperature. They can also stretch to three times their original size. In the study the printing was done onto a mock hand, although the next stage of the work is to print onto real human skin. These devices could be used to give robots touch sensitivity. 

Gibbon finding its voice

Whispering Gibbon, a software development company in Newcastle, UK, has received a six-figure investment from Creative England, a not-for-profit company that supports startups. The investment is to help the company launch its 3D printing technology, RenderFab, and a plug-in called Grabit. Renderfab can convert 3D models such as an architectural design into blueprints ready for 3D printing. Grabit allows companies to sell personalised 3D printed items to customers.

3D printed ovaries allow mouse to give birth

Scientists at Northwestern University, Illinois, USA, have 3D printed functioning ovaries. The team replaced a mouse’s ovary with the 3D printed bio prosthetic. The mouse was shown to not only ovulate but also give birth to healthy pups. The ovaries were produced using a gelatine scaffold that housed immature eggs. The team are excited about the gelatine scaffold as it exhibited a rigidity that allows for it to be handled during surgery and a porosity such that it can naturally interact with body tissues. This gives it potential for future use in helping infertile women be capable of giving birth. 

Protecting print designs

Researchers at New York University have discovered a way to protect 3D print CAD files from being stolen and copied and printed by criminals. The team discovered a way to hide a flaw within the CAD file so that stolen copies would be practically unprintable.  The defects would not appear if the file was printed from a manufacturer’s official system. Introduced defects include altering file resolution, printing directions and printer resolution.

Bioprinting pen used to repair sheep knee

The University of Wollongong and St Vincent’s Hospital in Melbourne have used a handheld bioprinter to print living cells in surgery to repair cartilage damage in sheep. The bio-printing pen was used to operate on eight sheep to repair one knee on each while the other was repaired in the currently common method. The scientists said that the biopen repair was markedly better in terms of quality and characteristics of new cartilage formation than the conventional method. The team plans to further study long term efficacy of the method in animals. 

3D printing medical sundries

Scientists at the University of Florida, USA, have developed a method for 3D printing sundry medical items such as a port for draining bodily fluids, implantable bands and soft catheters. The printing uses liquid silicone printed into a micro-organogel support material – this is a type of oily hydrogel that avoids the problem that conventional hydrogels pose when used with silicone, the layers separate like oil out of water. Having the support of the organogel allows for the printing of complex structures and enables printing of encapsulated parts which could have uses for guided drug delivery systems. The team believes that these silicone devices are ready for implanting now. 

Circuit printing with Eoprom

TriDInnov, a French 3D printing company, has developed a printing method, dubbed ‘additive metallization’, to turn plastics and composite materials into functioning circuit boards. The company developed an adhesive solution composed of metallic ions called Eoprom that can be printed directly onto 3D printed objects to create 3D or 2D printed circuits. Currently Eoprom can only be printed using Kelenn Technology’s DMD 100 printer. TriDInnov says Eoprom is low cost, non-toxic and ‘widely available’. Eoprom can also be printed onto flexible materials. 

Electrically conductive printing

The European Space Agency (ESA) has developed CubeSats that are printed using a doped PEEK (polyether ether ketone) material that is electrically conductive, strong, stable and has a melting point of 350°C. PEEK is conductive owing to the introduction of nano fillers. This means that when acting as a casing for CubeSats the usual nest of wires can be done away with and instead incorporated into the PEEK casing. The PEEK 3D printers are being optimized for space flight. The ESA sees 3D printed PEEK products being used in space to create objects that would usually need to be sent up to the space station, such as toothbrushes. A small PEEK-printed structural part is expected to be flying on the Meteosat Third Generation weather satellite by 2020. 
The Advanced Manufacturing Research Centre (AMRC), at the University of Sheffield, UK, has developed THREAD – a process that enables multiple threads of different materials used in electrical components to be inbuilt into products made through additive manufacturing methods. The THREAD method will be beneficial to manufacturers of components that require all electronics to be internal such as for medical prosthetics or consumer electronics. Components sealed into other materials could also be beneficial for components that need to be protected from the adverse effects of the environment. The AMRC is further developing the THREAD process for commercial markets. 

3D printed suturing device

Sutrue, a UK medical technology company, has 3D printed a device that helps surgeons when suturing. The device passes any curved needle with a suture through the tissue of a patient. The device uses a 3D printed gear mechanism to drive the suture needle. Sutrue claims the device can speed up the process of suturing eight-fold with it capable of three rotations per second compared to a manual rate of one stitch in 25 seconds. 

Stronger printed plastics

Essentium, a 3D printing company, demonstrated its FuseBox 3D printer that uses heat and electricity to increase the temperature of each layer as it is printed, essentially fusing them together. Essentium says that this layer-by-layer heating creates stronger finished products than FDM methods (fused deposition modelling), claiming that the finished parts are 95% as strong as parts created by injection moulding. This is achieved by the process of melting each layer post printing creating stronger layer-to-layer bonds. The company is now working to increase the printing speed of FuseBox to make it more commercially viable. 

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