How tentacles inspired design
This story was originally published in Turn The Page #62, November 2017
In the first week of my minor Biomedical Engineering — I did not exactly know what to expect — our guest speaker Paul Breedveld walked into the room and began with a lecture about something called ‘bio-inspired design’. I know the first few lectures are more likely to not only be physically, but also mentally attended by me than the lectures later on in the semester. However, this one really captivated my attention.
Bio-inspired Design
This so-called ‘bio-inspired design’ is a relatively new form of design that is inspired by nature, which some believe is the most minimalistic matter of all. It is really not as wishy washy as it sounds, since it is used to solve problems for great purposes in e.g. medicine fields, the environment and the manufacturing industry (think of smart materials).
It is noteworthy that often the term bio-inspired design is wrongly associated with a seemingly alike, but very different term ‘bio-based design’. This last form of design evolves around products that are composed of biological or renewable materials. Besides that, bio-inspired design sometimes is seen as a tool for designing robots or other simulations of living creatures, though robots are mostly imitations of human nature using mechanisms we already know of, like hinges, pulleys and gears.
“We are not imitating nature, since nature is not perfect either.”
As the name states, bio-inspired design is about inspiration, not imitation. Using this technique, we are not imitating nature — since nature is not perfect either, but we are looking at how nature’s creatures move, behave, coordinate and how they are constructed. Bio-inspired design is here to use nature as a source full of inspiration to engineer ‘new’ mechanisms, while keeping man-made devices in the back of our mind. Nature’s ingenious approaches can lead us to a more creative way of finding solutions.
Inspiration
Why do we get so intrigued by the designs of nature? I think the answer to this question can be found in some successful examples. Simple and maybe obvious examples are organ implants and prostheses. These can be bio-inspired: literally based on the substitute organ or limb.
A second form of application is in the manufacturing of new materials. Today we are able to create structures that have more favourable properties than the structures we already know, all based on examples in nature. Moreover, we can create structures that can sense, remember and respond.
A well-known example is the structural coloration in butterfly wings. These thin structures can reflect light in such a way they initiate bright and vivid colours. This had been mimicked by engineers and used in e.g. credit cards, passports and also colour displays in e-readers. Until 13 November, the TU Delft library hosts an exhibition with a lot of examples in surface innovative materials and structures based on nature. So if you are interested, quickly take a look before the exhibition takes off!
The tentacle design
Last but not least, I will finally introduce you to the design story of professor Paul Breedveld. Paul is part of the Bio-Inspired Technology Group of the TU Delft (BITE), where they develop innovative and bio-inspired technology for minimally invasive surgery. This kind of surgery has a limited size of incision needed, which results in an improved healing process.
Paul has been fascinated about octopuses and squids for some time, because they have no bones like we do. However, they can move in every direction; how is that possible? The tentacles of octopuses are build up by muscles that lay in different directions — there are circular muscles and straight muscle bundles that lay across the whole length of the tentacle. These muscles inspired Paul to create something he did not think of before; a flexible steerable endoscope.
Basically, an endoscope is a medical instrument that can look inside a human body. Nowadays these instruments are mostly rigid and have no wrist-alike joint. For that reason, it can move in limited degrees of freedom. Now try to tie your shoelaces without moving the joints in your arm; this is almost impossible. With these instruments, surgeons need to be very skilled to perform a difficult operation and they have a high risk of injuring the patient’s body.
Paul Breedveld’s solution is inspired by the squid’s tentacles’ anatomy. He used an iterative design process jumping from complexity to simplicity and back again. The first prototype consisted of just springs and cables resembling the muscles across the tentacles. Each step, each new prototype, the design became more complex and was then further developed into something more simple and thus easier to manufacture and understand. For now, this has resulted into different stadia of instruments that could crawl into a patient’s body and could turn all corners to operate more safely.
I hope I could convince you about the importance and overall amusement of finding inspiration in nature. What can we expect to happen using bio-inspired design? Maybe in the future we will all be swimming in swimsuits made of a sharkskin-inspired material. Or maybe the prostheses we create will function even better than our own limbs do. For now it might be only speculating, but I believe this way of creating can become revolutionary in all kinds of industries!
