Ouchless, residue-free, and durable: could beetles’ feet hold the secret to better bandages? Researchers from Korea and the US have used the same design that gives beetles their grip to invent a material that sticks to skin without any help from glue. Their work, published this month in the journal Advanced Materials, paves the way toward an improved form of medical adhesive.
Many medical treatments require adhesives that cling to skin to hold tubes or dressings in place. However, most use glue and can leave behind residue, irritate skin and lose stickiness, not to mention how much they can hurt to remove. These inconveniences become more serious for older patients who have fragile skin, meaning that a better material could really improve care.
The engineers took on this problem, but instead of trying to refine the glue, they designed a surface that is sticky on its own. They used PDMS, a non-toxic substance used in contact lenses, shampoo and food, and moulded it so that hundreds of thousands of tiny, mushroom-shaped ‘pillars’ covered every square centimetre. Once pillar size and spacing had been optimised for the texture of human skin, their product performed well in practical tests. It remained sticky after repeated removals and reapplications, left skin unharmed, and caused minimal pain to remove.
The ‘mushroom forest’ arrangement mimics beetles’ feet, where tiny mushroom-shaped hairs allow the beetle to cling to surfaces, taking advantage of forces of attraction on a molecular scale. While it’s not the first time engineers have tinkered with the beetle’s design secret, it is the first time that such an adhesive has been optimised for human skin. Further work is required to produce this glue-free adhesive on a large scale, but if that can be done, then we can expect the beetle-based bandage to stick around.
Read original paper here
Posted on Wednesday, 21st September, 2011
HMRC are estimating 150,000 SMEs in UK are not claiming at an average claim of £40k. By our calculation that makes £6bn/year!! Read the full story
Posted on Wednesday, 14th September, 2011
Could it now be possible to create materials that heal in response to light? Research into a new material, recently published in the journal Nature, has made this exciting concept a reality.
Polymers are the basis of plastics and resins. They are molecules that consist of a chain of identical, or similar, molecular units (monomers). DNA is an example of a biological polymer. The properties of the polymers then vary dependent on the combination of these molecular units or monomers.
A team of scientists from Switzerland and the USA have created supramolecular polymers that appear to heal when exposed to intense UV light. The material consists of rubbery polymers linked by metal ions. Just like chlorophyll absorbs sunlight to generate energy for photosynthesis in plants, the metal ions absorb light energy, which converts to heat energy instead. A build up of this heat energy causes the long chains of the polymers to temporarily loosen and then reform, removing any kinks or deformities.
An advantage of this light-healing process in materials such as plastics is that it can be applied much more locally than traditional heat-healing processes. As a result, the reforming process can target sites of damage without interfering with the material’s function. This advance would make repairs to plastics cheaper and easier, making them suitable for a wider range of applications. The technology is in its infancy at the moment, but it could be useful in several areas. For instance, incorporating the polymers into paints and varnishes could keep consumer products, such as mobile phones and iPods, scratch and crack free for longer, reducing waste. Sports car owners may be particularly interested; by making light work of any scratches or defects, it could bring an end to expensive scratch-repair bills.
Picture courtesy Dominique Bersier and Gina Fiore for Adolphe Merkle Institute, Case Western Reserve University, US Army Research Laboratory
Posted on Tuesday, 6th September, 2011