Complex items require a lot of 2D layers to be laid down during the 3D printing process; therefore, this procedure usually takes a long time. The technique typically results in significant material waste since it has to support the incomplete item. There are some inventive techniques for making flat materials fold into three dimensions, but they have drawbacks.
4D printing process. Specially created software turns an input 3D model, which can be a scan of an existing object, into a 2D pattern that can then be printed. The prints can then be submersed in hot water to self-fold into the final 3D object. Image Credit: Narumi et al. CC-BY-ND
For the first time, scientists combined 2D printing, origami, and chemistry to develop a technique for quickly fabricating 3D objects without producing any waste material. These shapes fold by themselves in a matter of seconds.
For a while, 3D printing was utilized to create product prototypes, and it is now increasingly being employed to create commercial goods, including components for jet engines. However, each method of 3D fabrication has its drawbacks, such as lengthy print durations or material waste during printing.
4D printing is a concept that seeks to address these challenges by utilizing a small number of materials chosen for the specific qualities that allow them to self-fold into complicated 3D forms under ideal circumstances.
The process of self-folding necessitates the use of time, which is commonly referred to as the fourth dimension. Ironically, a new speedy 4D printing technology begins in the 2D realm.
My team and I discovered how to use accessible tools and materials to create self-folding 4D objects. Essentially, we are creating flat sheets with origami patterns on them, and these patterns can be complex, taking even a skilled origami artist hour to form. But thanks to our special process, you can pour hot water over these flat sheets and watch as they spring into complex 3D shapes in a matter of seconds.
Koya Narumi, Project Assistant Professor, Department of Electrical Engineering and Information Systems, University of Tokyo
The method uses an inkjet printer specifically designed for printing UV-reactive materials. However, the equipment itself can cost tens of thousands of dollars. These printers are frequently seen in maker spaces and shared workshops.
A plastic sheet that shrinks with heat is printed on both sides with a 2D origami design using this printer. When dried, the ink it utilizes can stay flexible and does not shrink.
The designer can control the direction in a particular area of the sheet folds by creating gaps between sections of ink on one side or the other since the base sheet shrinks when heated and the ink resists the shrinking. The flat sheet is heated using hot water so that it folds into an elaborate origami design.
Narumi added, “Our biggest challenge was refining the options for hardware and materials, which took over a year to narrow it down to the final choices. But all the trial and error were worth it; compared to previous research around this same basic idea, we’ve improved the output resolution by 1,200 times, meaning the designs we can create are not just novelties, but can be used for real applications. In the future, we may explore functional materials, such as conductive or magnetic inks, that could allow for machines and other functional devices.”
Narumi and his colleagues are hoping that their invention can be useful in a variety of industries, including fashion, where there is frequently a high level of material waste, particularly in markets where customized designs are in demand.
However, since the pre-folded shapes are completely flat, there is also potential for this to be helpful in any circumstance where there are limited logistical or storage options.
Printed designs could even be mailed, and the receiver could then heat them to transform them into the item they requested. As well as this, there could be a utility in disaster recovery, when specific materials, perhaps including medical supplies, are necessary but are sometimes difficult to move, and it becomes a lot easier when the items required are practically flat.
Source: https://www.u-tokyo.ac.jp/en/index.html