This makes scientists able to print something akin to biological tissue. With the addition of live cells, those soft materials become bioinks. ‘The material has to be able to be extruded through a nozzle to print, but they also have to not be a liquid so that they don’t run away.’ ‘Every time you develop a new soft material to print, you have to do a battery of tests to make sure that it’s able to be printed,’ Annela says. However, soft materials are more hassle than plastics. Such materials are often natural in origin: gelatine, cellulose and alginate, which comes from seaweed. Source: © BSIP/Universal Images Group/Getty ImagesĪ structure printed with bioink at Zurich University of Applied Sciences (ZHAW) ‘You can imagine that they might have applications within the body.’

‘Materials that are kind of soft and squashy,’ Annela says. For that, they need a new set of printable materials. But what if you want to print something that isn’t made of plastic? A growing number of scientists are focused on printing objects that are similar to biological tissue. ‘Fused plastics … are quite well behaved and it’s easy to control them,’ says Annela. By using the right material, scientists can choose the properties of the final object. ‘We print a layer, and then we print another layer on the top, and then we print another layer on the top of that – that gives us a 3D structure,’ explains Annela Seddon, materials chemist at the University of Bristol. One of the main ways to do it is by squeezing a material, usually some kind of plastic that sets like glue, out through a nozzle and into a pattern. Going softĪs a concept, 3D printing is surprisingly simple. It links well to their study of natural polymers such a proteins and condensation polymers. This article provides an excellent opportunity for pupils to consider novel uses of polymers in 3D and 4D bioprinting. Even if that ‘anything’ is soft, squishy – and changing shape. Material chemists have continued to develop the technique, bringing us closer to a world where anything we can design on a computer, we can print in the lab. But what even he couldn’t have foreseen is how 3D printing is now no longer reserved for hard plastics. We can now print everything from cars to family homes, realising Daedalus’ vision of infinitely flexible production. While 3D printing wasn’t his craziest thought experiment (space elevator anyone?), it’s arguably the most useful. ‘Under programmed numerical control, the beams could reproduce any number of identical objects once the design had been optimised – silent, one-step, infinitely flexible mass production!’ continues chemist David Jones, the man behind Daedalus and DREADCO, in the earliest recognition of what could be achieved if we could print objects rather than just words.

Adding the fourth dimension: changing shape over time

3d vs 4d printing