By Lynne Friedman
Studying structures created by nature can lead to new man-made materials. Case in point, researchers at the Jacobs School of Engineering at UC San Diego are taking clues from seahorse tails in an effort to create a more flexible robotic arm.
Seahorse tails — made up of bony plates which slide past each other and that progressively decrease in size along the length of the tail — are exceptional flexibility and resilient. This “armor” design permits the tail to be compressed to half its size before permanent damage occurs, thereby thwarting sea turtles, crabs and birds attempting to prey on seahorses by crushing them.
A series of experiments produced detailed information on plate mineral composition, ratio of organic compounds to water, surface hardness, and ability to absorb impact. With this data, engineers used 3D printing to create artificial bony plates which can then be equipped with polymers acting as “muscles.” The ultimate goal: a hybrid between hard and soft robotic devices able to grasp a variety of objects of different shapes and sizes. Such a robotic arm would be valuable for use in medical devices, underwater exploration, and unmanned bomb detection and detonation.
Findings described in the journal Acta Biomaterialia. News release at
CO2 levels approaching milestone
For the first time in human history, concentrations of the greenhouse gas carbon dioxide (CO2) could rise above 400 parts per million (ppm).
Scientists estimate that the last time CO2 was as high as 400 ppm was the Pliocene epoch, between 3.2 million and 5 million years ago, when Earth’s climate was much warmer than today.
Scientists know so much about atmospheric greenhouse gas accumulation because of a continuous, daily record of CO2 measurements, begun in 1958, by the late Charles David Keeling, a renowned climate science pioneer at the Scripps Institution of Oceanography at UC San Diego. CO2 rises and falls in a sawtooth fashion, but the overall trend has been a consistent, unprecedented rise in CO2 levels.
The website keelingcurve. ucsd.edu offers background information about how CO2 is measured, the history of the Keeling Curve, and resources from other organizations on the current state of climate. An accompanying Twitter feed, @keeling_curve, provides followers with the most recent Keeling Curve CO2 reading in a daily tweet. News release at
Organism feasts on whale skeletons
Osedax is a genus of mouthless and gutless “bone worms” that thrives on skeletons lying on the seafloor. In a recent study, scientists at Scripps Institution of Oceanography at UC San Diego describe how the wispy worms are able to gain access to the nutrients within whale bones.
In a process remarkably similar to how mammals repair and remodel bone, Osedax secrete acid that dissolves bones, presumably releasing collagen and lipids that are absorbed by the worms.
Because they lack mouths, bone worms must use an alternative method of consuming nutrients and this has turned attention to symbiotic bacteria that live within the worms. Evidence suggests that the bacteria metabolize bone-derived collagen into other diverse organic compounds and that the worms subsequently digest the bacteria. The exact mechanism by which this process works, however, remains a mystery.
Findings appear in the Proceedings of the Royal Society B (Biological Sciences). News release at
Lynne Friedmann is a science writer based in Solana Beach.