How Do Snail Inspire the Industry?

Roofs are perhaps one of the most unappreciated things we have. It provides shelter to protect us from harsh weather conditions. Our homes, shopping complexes, schools, offices and factories all have roofs to provide protection from the harsh environment. In the recent years, roofs are more than just a shelter. While providing the necessary comfort, new designs to reduce environmental impacts and to generate electricity are a few characteristics of "green buildings" which take consideration of sustainable development when constructing a roof of a building.

Snails, just like humans do, like to hide themselves away from heat. 

Shells are fountain of inspiration for shelter and protection applications. Example of animals with shells are turtles, hermit crabs, and especially snails. In this post, we investigate how snail shells inspire designers to create roofs that reduce the heat of buildings and environments. In Malaysia, the weather is hot and humid throughout the year and with the rise of climate change, higher temperatures occur and intense solar radiation only make things worse especially in urban areas with large density buildings. Urban cities especially have higher temperature densities which result in 4℃ increase in surrounding temperature as compared to rural areas. This is known as the urban heat island effect.

Figure 1: White shells of the Sphincterochila boissieri 

Snails are masters of heat. The Sphincterochila boissieri snail (Figure 1) lives in the desert are only able to survive up to 50℃ even when their surrounding temperature may reach up to 65℃. By comparison, human bodies are normal at 37℃ and an increase of 1℃ in body temperature resulting in a fever of 38℃ is already a health risk. So how did the desert snail survive the heat? The answer lies in two important factors, heat reflection and intelligently manipulating and management of heat. Notice that the Sphincterochila boisseri snails have white shells to reflect radiation as up to a stunning 95% of sunlight is reflected with their shells.

To put this into perspective, if all roofs in urban areas were white as a snail's, global warming effect of 24 giga tonnes of greenhouse gas emissions will be reduced, equivalent to taking 300 million cars off the road for 20 years. NYC ℃oolRoofs, an organization in New York came about with a generous idea to gather volunteers to paint roofs with special treated white paint. To this day more than 6 million square feet (557 418.24 m²) of roof has been painted.

Figure 2: Shows the difference of temperatures of Base Case Colored roofs and White Coated roofs

Snails retract themselves to the upper part of their shells to escape from heat. And at the same time, the gap between the body of the snail and the soil below it provides a layer of air cushion insulation to greatly reduce heat intensity coming from the ground surface. As seen below, temperature of the surface can be as high as 65℃. The snails retract themselves to (b) position where temperature is just at 50℃. At (d), air cushion is produced as an insulation towards heat.

Figure 3: Illustration of Heat Flow and Reduction in a Snail Shell

Modern roofs use reflective bubble foams right under their roof tiles for the same reason as the snails did. To trap a layer of air cushion that will insulate the thermal heat from the inside of the house.

Figure 4: Foam Insulation applied to A Roof

Have you ever felt so frustrated waiting for the heat to go away from your hot leather seat after you leave your car or motorbike under the sun? Motorbike seat cover nowadays come with a new design with air cushion in mind. By elevating you by a few millimeters from the seat will ensure that you will never feel the heat even after your bike is left hours under the sun. Since this technology has been applied to motorbikes all over the world, it will be just a matter of time until our car seats are changed so. 

The smart use of heat also inspired a team of students to come out with an award winning building design. (Notice that the roofs are resigned to be white to reflect more heat)

Few noble inventions of the team were as follows: 

• In this form the space left between the shells is where the life flows. 
• Different spaces with different requirements can be adjusted to the form 
• Semi-open spaces provide the possibility of making a micro-climate 
• Semi-open spaces also act as a filter for the air entering the building – better ventilation 

Design inspired by the snail shell 

This view refers to different spaces that could be created by the shape of the form inside or even outside of the building

Flow of ventilation throughout the structure

Source: http://livingprinciples.aiga.org/snail-inspired-green-building-wins-biomimicry-student-design-competition/

Snail Inspired Science!

Biomimicry is the study of observation and the understanding of natural processes and functions in our ecosystem. By carefully studying an animal, plant or system we can learn their adaptations and apply the findings in engineering, architecture and medicine. This week, we'd like to discuss the bio-inspirations discovered from snails.

Snail Locomotion and Snail Trails

Secreted by a gland in the muscular foot

With three main purposes:

• Locating prey. Snails that feed on other snails sense the type of prey depending on the level and type of nutrients left behind on the trail.
• Used as energy source. The trail traps nutrients and then becomes a viable food source. The trail has high level of proteins and complex sugars.
• Suctioning device. Allows them to move upside down and vertically. 

Source: https://www.projectnoah.org/spottings/1512486034 

Current Research at MIT

• Associate professor Anette Hosoi in Department of Mechanical Engineering studies the sticky slime on their muscular underbellies in research of its mobility 
• They came out with a snail robot (RoboSnail) using a sticky gel which can climb on vertical surfaces or even upsidedown 
• Do not have exposed joints to prevent corrosion 
• Has potential to be all terrain robot to reach places like oil wells thousands of feet underground 

RoboSnail Prototype 

Robosnails

• Sticky gel made from Lapanite, a type of clay that forms clear and sticky gel when mixed with water 
• The fluid does not have to be non-Newtonian fluid. Any would do as long as its viscous enough 
• Three type of locomotion modes: undulating (tiny waves movement) from front to back, back to front 
• Galloping, sticks the front body to the front and then draws the rest of its body up behind 

Sourced:
http://bioweb.uwlax.edu/bio210/s2013/kopp_kayl/adaptation.htm
http://edition.cnn.com/2008/TECH/science/06/30/animal.robots/index.html?iref=newssearch
http://radio-weblogs.com/0105910/2003/09/07.html

Future tough martials inspired by sea snails

This Study is done in the following universities and laboratories:
At McGill University’s Laboratory for Advanced Materials and Bioinspiration &
at the Leibniz Institute for Interactive Materials in Aachen, Germany.

Introduction and some amazing facts about snail’s shell

The shells are made of a material called nacre, which is composed almost entirely of a brittle mineral. Remarkable organization of minerals results into sheets with tiny amounts of plastic-like proteins creating a complex system of sliding plates, nacre is over 3,000 times tougher than the mineral on its own! The inspiration from this feature is that nature takes materials that are not appealing in terms of strength or toughness and puts them together in way that produces high performance. This means purely through architecture we can completely change a material's behavior.

How this inspires a design of the glass!

With glass, the challenge is finding a balance between strength and toughness. Glass is strong. It doesn’t bend or deform over time, but is easily shattered by a sudden impact. Plastic, on the other hand, is tough. It can survive sudden impacts, but it bends and scratches easily but studies shows that abalone shells, amazingly, combine the best features of both and this is where the inspiration starts. There are experiments underway to create glass that can absorb direct impacts from steel balls, and is more bendable than ever before. 

How snail’s shell does it?

The sliding plate structure of nacre allows the brittle mineral to shift when force is applied, adding to its toughness. When a shell is hit, force is deflected away from the site of impact down microscopic pathways of low resistance and taken on what scientists call a “tortuous route.” The energy applied to the nacre is divides into angles and goes through some certain pathways because of the architecture of the nacre and eventually the force is too weak to crack anything. This arrangement can be used in the glass design and be taken further into all the existing materials by introducing micro-architectural features based on natural models, they could change the properties of existing materials.

Implementation

Using computer programs that can model impacts on glass, the scientists designed their own system of paths. They used a laser to etch their configurations onto existing sheets of glass, and found that the glass with channels was 200 times tougher than before. This architecture have to be tailored in to the application where in the first trial a type of jigsaw architecture was used that works well for pulling force. In a forthcoming paper, the scientists describe a new type of glass that is over 900 times tougher than untreated sheets. The interlocking brick-like maze etched into the glass is filled with flexible polyurethane, and closely resembles natural abalone shell.

Microscopic jigsaw architecture design embedded into glass

How nature assembles building blocks into complex structures—without factories and huge amounts of power?

In a paper from January the group revealed that they had developed a system to coat the minerals in a flexible polymer and guide the mixture to assemble itself into paper-like sheets. “Mussels grow nacre in a lengthy process. For our nanocomposites, we instead apply a rapid self-assembly process," Dr. Walther said, and noted in the paper that producing a sheet of the artificial nacre-like composite took less than a day. The new process is also a significant step towards simple, sustainable manufacturing of these materials. One of the most appealing aspects of bio-inspired materials is the way in which nature assembles building blocks into complex structures—without factories and huge amounts of power. 

The shell of a limpet is the strongest natural material in the world

Researchers at the University of Portsmouth examined the mechanics of limpet teeth by pulling them apart all the way down to the level of the atom.

"Until now we thought that spider silk was the strongest biological material because of its super-strength and potential applications in everything from bullet-proof vests to computer electronics, but now we have discovered that limpet teeth exhibit a strength that is potentially higher," said Professor Asa Barber, who led the study.

A highly magnified image of limpet teeth. Credit: University of Portsmouth. 

The study, published in the Royal Society journal Interface, found that the teeth contain a hard material known as goethite, which forms in the limpet as it grows. Limpets need the high-strength teeth to rasp over rock surfaces and remove algae for feed when the tide is in. 

"We discovered that the fibres of goethite are just the right size to make up a resilient composite structure," Asa said. "This discovery means that the fibrous structures found in limpet teeth could be mimicked and used in high-performance engineering applications such as Formula 1 racing cars, the hulls of boats and aircraft structures. 

"Engineers are always interested in making these structures stronger to improve their performance or lighter so they use less material." Limpets' teeth were also found to be the same strength, no matter what the size. "Generally a big structure has lots of flaws and can break more easily than a smaller structure, which has fewer flaws and is stronger," Asa said. 

"The problem is that most structures have to be fairly big, so they're weaker than we would like. Limpet teeth break this rule as their strength is the same no matter what the size.” 

Source: 

http://www.australiangeographic.com.au/news/2015/02/sea-snail-shell-the-worlds-strongest-material 

http://rsif.royalsocietypublishing.org/content/12/105/20141326.e-letters

Slow Tile: Colored Snail Poo Makes Vibrant Materials

Seen over at Dezeen and currently on view at the Biodesign show at The New Institute in Rotterdam, Schreuder apparently chanced upon this idea after observing in her ravaged garden that the little critters were also fond of eating paper and cardboard -- materials that have a similar cellular structure to their preferred plant food.

She then decided to test a hypothesis: what would happen if they ate colored paper? A trip to a snail farm later, Schreuder discovered that the snails' systems will not absorb most of the coloring, instead resulting in vibrantly colored feces, which the she says has a malleable feel.

This carpet would take a while to produce, though, as Schreuder admits that her filaments of poop (which when processed measure 5-millimeters wide) are made literally at a snail's pace. One metre of thread will take me an hour and contains six grams of excrement that is ground before processing. It will take approximately nine snails five days to produce these six grams. Practical? Probably not. And maybe it might be better to eschew the color altogether (seeing that no one asked the snails). But certainly intriguing, once we figure out what other uses snail feces may have. 

Look at all the mushi poops sticked on its cage cover!

Source: 
http://www.treehugger.com/sustainable-product-design/tiles-made-coloured-snail-poop-lieske-schreuder.html

A New Kind of Body Armor, Courtesy of Bottom-Dwelling Snails

A snail might not sounds like an ideal inspiration for a defense system, but one unique, deep-sea dwelling mollusk could serve as the model for a new kind of body armor, based on its ability to repel crab attacks. The scaly-foot gastropod, discovered a decade ago living near thermal vents nearly 8,000 feet below the ocean surface, possesses a unique three-layer design in its shell that could be extrapolated to such diverse products as flak jackets, helmets, Arctic pipelines and motorcycles.

MIT researchers studying the snail's shell found that the shell's outer layer consists of iron sulphide particles that come from the hydrothermal vents, each embedded in a matrix secreted by the snail. When struck as it would be by bottom-dwelling predators like crabs, the outer layer cracks in a way that absorbs energy and reduces impact to layers underneath. Tiny cracks spread around the iron sulphide particles, which ensure that larger cracks don't form even while absorbing the brunt of the blow.

A second spongy layer further absorbs impact and keeps the snail's fragile calcium carbonate inner shell from cracking, a critical function, as the acidic water near hydrothermal vents would quickly begin to dissolve the inner shell at the point of fracture, causing small cracks to grow.

Like snails, humans naturally want to contain the damage of an impact to our outermost layers. Researchers envision a body armor coated in iron-based nanoparticles that could greatly blunt and distribute the impact of a blow by creating microcracks similar to the ones in the outer layer of the snail's shell. A similar construction could be lent to fiberglass-like panels used in vehicles, or in a casing for pipelines that are regularly impacted by icebergs.

Source:
http://www.popsci.com/technology/article/2010-01/new-kind-body-armor-courtesy-bottom-dwelling-snails

Dazzling 'glow snails' use light for defence

Scientist have discovered how a bioluminescent Australian sea snail is able to use its shell like a lampshade, filtering the light given off from naturally glowing cells to ward off predators. Flashes of green light, or bioluminescence, produced by Hinea brasiliana, a snail found on the eastern seaboard, have long puzzled marine biologists. When gathered in large groups, their collective glow can be seen from the shore in Sydney and other eastern coastal spots. 

Trick of the light

"Bioluminescence is a common communication method in open water molluscs like squid, but is much rarer in marine snails that live on the bottom," says Dr Nerida Wilson of the Australian Museum in Sydney. "[However,] one snail family has several members that can produce light; these are commonly known 'clusterwinks' because they group together in crevices at low tide on the rocky shore." 

Now, a new study led by Nerida and Dr Dimitri Deheyn at the Scripps Institute of Oceanography in the USA, has discovered how the snail uses its shell to regulate the glowing light show for defence. To test the source of the bioluminescence, the researchers collected specimens from seaside rock crevices and then examined them in the laboratory.

Filtering the light

"Hinea brasiliana produces light from two patches of cells on a part of its body that is always hidden underneath its shell," says Nerida. Discovering how the snail spreads the light was a surprise, as the species has an opaque, yellowish shell that looks like it would stifle light diffusion. 

However, the pair found that when the snail produces green bioluminescence from its body, the shell acts as a mechanism to specifically filter and disperse the light. The resulting glow, which lights the shell up like a lampshade, is typically emitted to ward off predators by making the snails appear larger than they actually are. 

The study is published this week in the journal Proceedings of the Royal Society B. The research will now be extended to test if other snail species possess similar abilities, Nerida says. 

Source: 
http://www.australiangeographic.com.au/news/2010/12/dazzling-glow-snails-use-light-for-defence

“When we look at what is truly sustainable, the only real model that has worked over long periods of time is the natural world.”

-Janine Benyus