JOIN USIf you think origami is paper art, and can only be a past-time or a means of entertainment, think again. Apart from serving as an engaging hobby, the art has serious uses in science. If recent reports in professional science journals are any indication, origami has become very serious business. World over, scientists are folding papers and molecules to arrive at a useful shape.
Origami is a Japanese craft where a flat piece of paper is given a three-dimensional shape by way of creases and foldings. Paper is creased first and folded across the creases to create what origami-practitioners call elevations and valleys – the raised portions or depressions. Depending upon how the paper is creased and folded, shapes from simple boxes to elaborate figures can be created.
Mathematicians have wondered at the geometry and mathematical beauty of origami shapes. But in the hands of serious scientists, the paper folding craft is turning out to be an imaginative research tool. From finding solutions for a down-to-earth problem of designing a shopping bag to creating microscopic structures, scientists are creatively using origami tricks.
Origami could be useful in outer space. The solar sails which power the artificial satellites remain folded at launch, and once in space, they are unfolded, much like an origami flower, into their full shape and size. That allows scientists to pack a huge sail in a small satellite.
In the micro world too, origami could be useful. Take for example, MEMS (micro electromechanical systems), which is about devising miniature robots, pumping stations or electronic circuits that are used to analyse or identify chemicals, deliver specific quantities of drugs as and when desired or are used as mini-robots to move around the body performing different tasks. There is a catch, however. Most MEMS devices require semi-conducting or conducting properties. The materials of choice for construction are hard metals or silicon wafers. This limits the fabrication to flat two-dimensional devices and devising any other shape requires high skills and tools for manipulating these materials at micro dimensions. Micro electromechanical systems, thus, remain largely concepts.
Living shapes & forms
Providing artificial scaffolds for living cells to building an artificial kidney or liver is another area where hard materials have to be manipulated into complex shapes and forms.
Jennifer A Lewis, a materials scientist and engineer at the University of Illinois, Urbana, USA thinks that origami could be of help in this regard. The craft, which gives a flat paper three-dimensional shape, could work even at micro dimensions.
Publishing her results in Advanced Materials, she has shown how a penny-sized titanium hydride origami peacock can be easily created using origami. Prof Lewis has also created boxes, cages and various types of spiral tubes, all tinier than two mm. All one needs for this trick is a soft pliable platform over which the metal is pasted in thin strips or ribbons.
Using ink-jet printing technology, intricate designs can also be created. This is then folded using origami techniques into desired shape after which the soft base is removed to leave behind a hard, 3-D shape. “These meso-scale objects could find potential applications in tissue scaffolds, biomedical devices or catalytic supports,” opines Lewis.
Then there is DNA origami involving manipulation of Deoxy Ribonucleic Acid (DNA), the chemical which carries all our genetic information in its make-up. The molecule has a peculiar property. A piece of DNA can recognise and stick to another piece in a definite way. Scientists believe that this property could be gainfully used to fabricate a few atoms thick shapes. Nadrian A Seeman, a Chemistry professor at the University of New York, New York, USA, with some deft chemistry has created a sort of a DNA-Lego block which looks like a Red-Cross logo. In a suitable chemical environ, the blocks can assemble themselves into elegant mats. How many of them stick together and into what shape can be controlled to get a desired size and shape of DNA mat. The Lego was created by aligning several strands of DNA side by side and tying them across in the middle with suitable chemical bridges. Two such DNA pieces were straddled across to create the Plus-sign Lego.
Mobius strip from origami
According to Prof Seeman, the technique provides a novel ‘bottom-up approach’, for building complex structures using simple building blocks. Twisted ribbons and even the mobius strips have been created using these origami techniques. Hao Yan, a material scientist at the Arizona State University, USA, has shaped a mobius strip of DNA, tied it at several places and cut it to create interlocking rings. As we all know, the mobius strip is a plane figure, a circular ribbon twisted at one place. Although it appears to have two surfaces, it possesses a single surface and is a mathematical curiosity. When cut lengthwise, the strip transforms into two tangled rings. As things appear, only imagination seems to be the limitation.
There are also more down-to-earth applications for origami. It can help design shopping bags too. Surprised? Ordinary shopping bags are folded from a relatively flexible paper. It is difficult to fold more rigid material such as corrugated board or metal sheets into bags.
However much useful, paper shopping bags are rather frail. If the bottom is too big, the bag becomes too short. If you design a tall bag, the bottom becomes slimmer. Only thin paper could be folded into bags. If a thick and hardier cardboard is folded, the bag becomes unwieldy for storage. Also, a bag when ‘collapsed’ flat occupies more space than its base.
Is there a different way to fold a thick paper into a large bag? The problem has puzzled Prof Zhong You, an Engineering professor at the University of Oxford, UK, so much that he has come up with a mathematical solution, using origami techniques, to fold flat rigid surfaces into shopping bags. Prof Zhong has derived a mathematical formula which indicates the number and position of creases to fold a flat board into a tall shopping bag.
By adding a few extra creases at specific places, they have created a metal bag. The entire bag can then be ‘collapsed’ flat, to match exactly its base, which means stacking of hundreds of them will need less space and is easy task. The idea, confesses Prof Zhong, came from origami techniques he learnt while working on DNA origami.