a4.2 - c2b longchamps

John Longchamps Denise DeLuca Biomimetic Design MCAD | Summer 2015

A4.2 Challenge to Biology

1.1 Identify Design: A sustainable hydrophobic jacket that is rated for moderate temperatures.

Functions:

The outer layer must remain completely hydrophobic

Must be rated for moderately cool temperatures down to 32 degrees Fahrenheit

Conditions:

The jacket will be worn mostly in temperate urban areas during rainy spring and fall seasons.

1.2 Translate Biological Functions: hydrophobic, durability, ease of fit, temperature regulation

How does nature produce hydrophobic surfaces?

Biological Conditions: water (rain), airborne particulate, varying temperatures

What kind of environments in nature have water?

1.3 Discover (bullets below are paraphrased from AskNature) How does nature leverage hydrophobic material properties in wet or rainy environments?

Lichen uses hydrophobic surfaces to allow gas exchange in saturated conditions

Morpho butterflies shed water and dirt via hydrophobic microstructures on wing materials

The feathers of penguins prevent water from penetrating to the skin due to their stiff, tightly

packed structure

“When diving, the penguin requires a thin, smooth and waterproof coat with no trapped air

(positive buoyancy would be a big disadvantage to an active swimming hunter). It achieves this

by using muscles attached to the shaft of the feather to 'lock down' the feathers to create a

water-tight barrier.”


Images: asknature.org


1.4 Abstract Technical Strategies:

Utilize hydrophobic materials in a way that allows for gas exchange (air flow) in saturated (rainy)

conditions

Shed water via hydrophobic outer layer of jacket by tightly packing woven fibers used in the

creation of patterned textiles

1.5 Emulate Design Concept:

A textile will be developed that tightly weaves lance-shaped fibers into an evenly arranged

pattern to create an impermeable outer layer for the jacket.

1.6 Evaluate The woven pattern of the outer shell textile aligns with the principle of “shape rather than

material.”

The then internal down feather layer aligns with the principle of “locally attuned and

responsive.”

2.1 Identify Design: A sustainable puncture-resistant jacket.

Functions:

Must have exceptional durability including tensile strength and puncture resistance

Conditions:

The jacket will be worn in urban environments that contain concrete, brick, steel, and wood

surfaces and structures that may have sharp edges, and could cause damage to non-resilient

materials.

2.2 Translate Biological Functions: durability, structural impermeability

How does nature produce durable materials?

How does nature leverage durable materials?

Biological Conditions: sharp forms within the environment that can puncture materials and tissue.

What kind of natural environments have sharp objects and organisms that resist puncture?


2.3 Discover (bullets below are paraphrased from AskNature) How does nature resist puncture from sharp objects?

The leaves of grasses resist crosswise tearing due to their composite character

Leaves of brown algae survive extreme mechanical battering because of their sandwiched

texture

The hooves of horses resist cracking by having braided filaments of keratin in horizontal sheets

punctuated vertically by thin, hollow tubes

The spicules of sponges help prevent cracking via their long, thin shape and orientation

transverse to load direction

Image: https://instruction.cvhs.okstate.edu/Histology/HistologyReference/HRHoofframe.htm


Weave textile that resists vertical and horizontal tearing due to braided fibers punctuated by

vertical nanotubes

Sandwich the finished textiles described above in layers to create resistance to force



The jacket will utilize a robust outer layer comprised of sandwiched sheets of deliberately

arranged woven textile to resist puncture.


material.”

3.1 Identify Design: A sustainable temperature regulating jacket specialized for moderate temperatures.

Functions:

Must be rated for moderately cool temperatures down to 32 degrees Fahrenheit

Conditions:

During spring and fall, temperatures consistently rise above 60 degrees, therefore there must be

ventilation for the wearer who will expect a comfortable internal jacket temperature while they

are staying dry in the jacket.

3.2 Translate Biological Functions: hydrophobic, durability, ease of fit, temperature regulation

How does nature regulate temperature?

Biological Conditions: water (rain), airborne particulate, varying temperatures

What kind of environments in nature have varying temperatures?

3.3 Discover (bullets below are paraphrased from AskNature) How does nature regulate temperature?

Silk moth cocoons allow carbon dioxide to diffuse out but not in and regulate temperature

through calcium oxalate hydrate crystals and cocoon architecture.


The skin of elephants allows them to fine-tune thermal regulation via ‘hot spots’, patches of skin

that are highly vascularized.

"By directing their blood supply near the surface of small patches of skin scattered around their

bodies, elephants can lose heat rapidly, allowing them to fine-tune their internal temperature."

(Gray 2010)

Image: https://instruction.cvhs.okstate.edu/Histology/HistologyReference/HRHoofframe.htm


Create textile architecture that emulates high-density vascularity


The jacket’s outer layer will downregulate temperature through utilizing outer layer textiles that

regulate temperature via fiber architecture. High density vascularity, such as that found in

elephant skin will be emulated in the form of laterally suspended micro tubes woven in to the

primary textile fiber in strategically placed “hot-spots” – this will also downregulate

temperature. The jacket will have a thin internal down feather layer to upregulate temperatures

down to and including 32 degrees Fahrenheit.


material.”

The emulation of elephant skin vascularity aligns with the principle of redundancy.


Final Design

Total Biomimetic Design Strategies to Achieve Desired Functionality: The final sustainable jacket design is puncture-resistant, hydrophobic, and temperature-regulating.

Puncture resistance is achieved by weaving fibers into braids punctuated by laterally positioned micro-

tubes. Sandwiched textile layers create additional resistance to force. Finally, the jacket’s outer-layer

downregulates temperature using laterally suspended micro tubes woven in to the primary textile fiber

in strategically placed “hot-spots.” Temperature is upregulated using a thin internal down feather layer.