Two BSc students on the Design and Innovation study programme were looking for an alternative to steel insulin needles, and drew inspiration from the world of animals in designing a new plastic needle.
Millions of people suffer from diabetes and have to inject themselves with insulin several times a day. This currently involves using steel needles, which are expensive to make and difficult to dispose of. Many patients consider their needles to be reuseable—even though they may have dropped them on the floor—which can lead to bacterial infections and may even result in the needle tip breaking off under the skin.
Plastic may provide a useful alternative to steel, because plastic needles are cheap to make and can be injection moulded in a single process. Unfortunately, no-one has yet succeeded in creating a plastic needle that is thin enough and rigid enough to penetrate the skin without bending or breaking.
Torben Anker Lenau, Associate Professor at DTU Mechanical Engineering is working on the problem and involving his students in the work. Two of them—Ronja Pereira Haase and Marianne von Freiesleben—who are both taking a BSc in Design and Innovation set about the problem with such enthusiasm that their work was awarded the title of ‘BSc project of the year’ by the consultancy company Accenture.
“We thought that as there are so many things in nature that can scratch yourself on, there had to be something other than metal that can puncture the skin. We did a bit of brainstorming and identified some appropriate animals, read up on their biology and attempted to isolate a few principles,” relates Ronja. Torben adds that a lot of animals are actually composed—either fully or in part—of materials whose structure resembles polymers such as plastic.
The sea urchin’s teeth, the gnat’s proboscis and even the stinging nettle’s tiny ‘blades’ were all examined in detail, but the most inspiring find of all was the porcupine’s quills, which pass through the skin twice as easily as a medical needle. The young students succeeded in convincing the Zoological Museum to lend them some porcupine quills, and using a mixture of technical skill and zoological knowledge, they came up with a useable plastic needle.
Being their own hardest critics, the two students were amazed that their project was rated so highly by Accenture. They have, of course, had to hurry on with their study programme, but they are now thinking about whether it might be an idea to patent their invention.