Uterus Expands/contracts

Biological Strategy

Mammals

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Modify Size/Shape/Mass/Volume

Many living systems alter their physical properties, such as size, shape, mass, or volume. These modifications occur in response to the living system’s needs and/or changing environmental conditions. For example, they may do this to move more efficiently, escape predators, recover from damage, or for many other reasons. These modifications require appropriate response rates and levels. Modifying any of these properties requires materials to enable such changes, cues to make the changes, and mechanisms to control them. An example is the porcupine fish, which protects itself from predators by taking sips of water or air to inflate its body and to erect spines embedded in its skin.

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Prevent Fracture/Rupture

High force impact or stress can cause materials that comprise living systems to separate into two or more pieces (called fracturing) or to break or burst suddenly (called rupturing). For example, a scallop prevents structural failure from fracture because its shell is comprised of two materials of varying stiffness. When a crack moves from the scallop’s stiff material to the less stiff one, the latter reduces the force at the tip of the crack, thereby stopping it from spreading farther.

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Mammals

Class Mammalia (“breast”): Bats, cats, whales, horses, humans

Mammals make up less than 1% of all animals on earth, but they include some of the most well-known species. We know first-hand some of the characteristics that make mammals unique, like having hair, being able to sweat, and producing milk through mammary glands. Another critical shared feature is a set of highly-specialized teeth. Unlike sharks or alligators, for example, whose teeth are generally all the same size and shape, mammals have differently shaped teeth in different areas of the jaws to target specific foods or foraging strategies.

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The uterus of female mammals can expand and contract to accommodate its contents thanks to spiral muscle fibers in its central myometrial layer.

“Similarly, the uterus of female mammals must expand and contract with gestation and birth, often an order of magnitude (ten-fold). The hooped fibers of chitin in the locust are paralleled in the interior circular muscle fibers of the uterus. Of the three layers of the uterus, the central myometrial layer is responsible for the expansion and contraction of the uterus. It is composed of connective tissue, mainly smooth muscle fibers with an external layer laid longitudinally and an internal layer laid circularly at the base which then spirals in both directions around the uterine body (which might even be a logarithmic spiral…).

The lessons from these ‘hooped’ chitin fibers and spiral muscle fibers could be incorporated into a packaging material, thereby allowing for expansion and contraction of the packaging depending on the size of its contents. The result of packing multiple items into a shipping case would be the absolute minimization of air space between objects created by the packaging alone. Additionally, the same packaging product could be specified for a large variety of object sizes, i.e. the bag holding the baby shoe would be the same SKU as the one holding the basketball shoe or the soccer ball.” ( 3.8 unpublished report)

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