Resisting Buckling With Sea Sponges

Orange puffball sea sponges may look like the unwanted sponges that can have any structural strength. However, it is a challenge for them to keep up their shape at the bottom of ocean that has churning waves all the time. According to a latest research, that these creatures have very minute structural rods that have developed to maintain their optimal shape and keep away buckling under great pressure. These rods are known as strongloxea spicules and are almost 2mm long. These are thinner than any human hair strand. When hundreds of these get bundled together, these lead to formation of a highly strong rib like structure that are present inside this sponge’s body.

The team made use of structural mechanics models and did little investigation in the old mathematical journals. The research was carried by two Brown University engineers named, Michael Monn and Haneesh Kesari. The two were successful in displaying a specific shape of these spicules that had optimal resistance for buckling which happens to be the basic force that leads to failure in formation of slender structure. The natural structure of this one can offer blueprint for enhancing the buckling resistance for all types of slender human-made structures. This can include bicycle spokes to building columns, and all other relevant stuff.

Kesari says, “This is one of the rare examples that we’re aware of where a natural structure is not just well-suited for a given function, but actually approaches a theoretical optimum. There’s no engineering analog for this shape — we don’t see any columns or other slender structures that are tapered in this way. So in this case, nature has shown us something quite new that we think could be useful in engineering.”

The Mediterranean Sea is home to orange puffball sponges and these organisms are mostly found in the rocky coastal environments. This brings a consistent stress over them with tidal forces and underwater waves. Sponges are more like filter feeders that pump water via their internal bodies for extraction of oxygen and nutrients. In order to accomplish this, these bodies need to be compliant and porous but these also need to be strong enough to keep away the stress that can lead to unwanted deformation. Kesari further says, “If you compress them too much, you’re essentially choking them. So maintaining their stiffness is critical to their survival.”