It's also interesting because the original work on riblets as drag reduction surfaces on aircraft, was abandoned, at least in part, because they couldn't keep the surfaces clean! But hasn't Toni Kesel at Bremen been working on exactly the same thing - shark skin as an anti-fouling surface?
Coming back to the surface structure, certainly many beetles (which I have observed closely many years ago) have all sorts of microstructures on their surfaces, including lots of microstriae. Of course because they are always there they excite no interest. But perhaps they are a similar sort of defence mechanism. Only thing is that shark denticles presumably move against each other as the shark swims. Beetle cuticle is made of large(ish) plates, often much larger than denticles. Many plant cuticles are similarly sculpted. Christoph Neinhuis should know.
Julian
On 16 May 2013, at 20:27, Adrian Bowyer wrote:
> That is rather interesting, not least because it seems to initiate a whole new field of research:
>
> Micro-geometries that inhibit quorum sensing.
>
> I would not be surprised if vast areas (literally) of plant and animal surfaces had evolved to do precisely that. Lungs, anyone?
>
> Best wishes
>
> Adrian
>
> Dr Adrian Bowyer
> http://adrianbowyer.net
>
> On 16/05/13 20:14, MECHOLSKY,JOHN JOSEPH,JR wrote:
>> Do you know about Sharklet? It was inspired by sharkskin: http://www.sharklet.com/technology/
>>
>> Jack
>>
>> John J. Mecholsky, Jr., Ph.D
>> Materials Science & Engineering Department
>> 237A Rhines Hall
>> PO Box 116400
>> University of Florida
>> Gainesville, FL 32611-6400
>>
>> Telephone: 352 846 3306
>> FAX: 352 846 3355
>>
>> -----Original Message-----
>> From: Engineers and biologists mechanical design list [mailto:[log in to unmask]] On Behalf Of Julian Vincent
>> Sent: Thursday, May 16, 2013 9:45 AM
>> To: [log in to unmask]
>> Subject: Re: Ghosties
>>
>> I certainly try to stick to that positive viewpoint. However - - mention of shark skin brings up another problem. How many biomimetic design solutions are actually due to physicists and engineers having worked out how a particular phenomenon works, then it's been recognised in biology and hailed as a new phenomenon? Shark skin certainly falls into that category.
>> Velcro is good, though, so are cats' eyes as road markings and Lotus effect. I think gecko tape is OK. I agree that a prep. list would be a useful thing.
>> One of the problems about doing science is knowing the history behind various ideas. I am reading Gerry Pollack's latest book on the strange physics of water. He describes what he calls the exclusion zone - a layer of water molecules about 100 µm thick built up rapidly against a surface - that he discovered and has studied. It's been known in biology for quite a few years under the name of the unstirred layer, but Gerry found that out only later. I suspect biomimetics is in the same category - if you don't know your history you are condemned to relive it. If you *do* know your history you can apply some of the earlier ideas - which is what happened with shark skin, once the full connection had been made.
>>
>> Julian
>>
>> On 16 May 2013, at 14:17, Daniel Weihs wrote:
>>
>>> Hello Julian
>>>
>>> The best way is to describe real biomimetic systems that are of public
>>> interest, and well known ( but not the biomimetic aspect) Thus
>>> sharkskin drag reducing surfaces, Velcro , etc. are good examples,
>>> that all of us, when talking with the public , should point out. A
>>> prep. List may be useful
>>>
>>> Danny
>>>
>>> -----Original Message-----
>>> From: Engineers and biologists mechanical design list
>>> [mailto:[log in to unmask]] On Behalf Of Julian Vincent
>>> Sent: Thursday, May 16, 2013 3:16 PM
>>> To: [log in to unmask]
>>> Subject: Ghosties
>>>
>>> There are quite a few stories which do the rounds regularly of systems
>>> which purport to be derived biomimetically and are nothing of the
>>> sort. I have researched some of these, since it seems to me that it's
>>> important to sort out how ideas can profitably be moved from biology
>>> to technology, and counter-examples might be useful as examples of
>>> bad science, wishful thinking, post hoc propter hoc, etc.
>>>
>>> The ones I know of are:
>>>
>>> **Roof of the Crystal Palace: The corrugated roof was invented in
>>> 1810 or earlier by John Claudius Loudon, an inventive
>>> horticulturalist, some 40 years before the Crystal Palace was designed
>>> and (as far as I can tell) before people in the UK had come across the
>>> floating leaves of the lily, Amazonica.. The corrugated roof bears no
>>> relation to the leaves of lily, but the half-round arch which tops the
>>> Crystal Palace (not present in the original drawings) is very
>>> reminiscent of the leaf in its design. There may be a connection there. A result of lax reportage by the Press?
>>> **Eiffel Tower: This was the first structure to be designed according
>>> to wind loadings. Its hierarchical strutted structure is probably a
>>> result of limited access to the site. The Tower is nothing to do with
>>> the structure of bones, tulip stems, or anything else biological.
>>> **Sydney Opera House: Nothing whatsoever to do with shells. It's a
>>> shell structure, but that's a technical description. Nothing in the
>>> original accounts of its design or structure says anything about a biomimetic origin.
>>> **Polar Bear light guides: The bear's hair does not function as a
>>> light guide (shown experimentally) although light guides arranged in
>>> the same way can have useful properties.
>>> **Eastgate Centre, Harare: Doesn't work like a termite mound
>>> (technically as a stack - chimney - which can draw air through the
>>> system) because termite mounds don't work like that! The building was
>>> designed before people understood how the nest's gas exchange system
>>> really works (it seems to be more like our lungs, semi-tidal and not
>>> mixing very much). And people ignore that insects can cope with a
>>> wide range of CO2 in the air surrounding them.
>>>
>>> Any more to add to this hit list (there must be!)?
>>> How do we rectify these fairy tales?
>>>
>>> Julian Vincent
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