450-Million-Year-Old Organism Rebuilt as a “Soft” Robot

Scientists have breathed new life into a 450-million-year-old organism, using fossil records to build a robotic replica out of flexible electronics and soft materials.

The new soft robot, called the “Rhombot,” is based on an ancient marine organism known as the pleurocystitid. This robot, and others like it, could be used to better understand the biomechanical factors that drove evolution in the distant past, the researchers say.

The research is published in the Proceedings of the National Academy of Sciences.

The field of Paleobionics

The earliest fossil records for early modern humans date back roughly 300,000 years. But in the span of the Earth’s existence, this is a mere blink of an eye – only 0.007% of the planet’s history. While the study of the modern-day animal kingdom continues to shed new light on evolution and offers a source of inspiration to today’s engineers, this is also just a snapshot of all of the creatures that have existed throughout history.

To broaden our understanding of evolution, animal design and movement, some researchers are casting their eyes further back. In this new research, scientists from the Carnegie Mellon University (CMU) Department of Mechanical Engineering, alongside paleontologists from Poland’s Institute of Paleobiology and Spain’s Geological and Mining Institute, are introducing a new field of study – Paleobionics.

This field is aimed at using Softbotics – an approach to robotics that makes use of flexible electronics and soft materials – to study ancient lifeforms with the goal of understanding their biomechanics.

“Our goal is to use Softbotics to bring biological systems back to life, in the sense that we can mimic them to understand how they operated,” said Philip LeDuc, the William J. Brown Professor of Mechanical Engineering at CMU.

“Softbotics is another approach to inform science using soft materials to construct flexible robot limbs and appendages,” explained Carmel Majidi, lead study author and the Clarence H. Adamson Professor of Mechanical Engineering at CMU. “A lot of fundamental principles of biology and nature can only fully be explained if we look back at the evolutionary timeline of how animals evolved. We are building robot analogs to study how locomotion has changed.”

Recreating pleurocystitids

The pleurocystitid was a member of the echinoderm class of animals, like modern-day starfish and sea urchins, and is believed to be one of the first echinoderms capable of movement using its muscular stem. While there is no direct modern-day equivalent to this ancient echinoderm, pleurocystitids have become a species of interest to paleontologists due to the pivotal role that they played in echinoderm evolution.

In the new study, the research team used fossil evidence to guide the creation of a pleurocystitid-like robot, using a combination of 3D-printed elements and polymers to mimic the flexible columnar structure of the pleurocystitid’s moving tail-like appendage.

They demonstrated how the ancient pleurocystitids were likely able to move over the terrain on the bottom of the sea floor using their stem, making wide sweeping movements to push themselves forward. The researchers found that pleurocystitids could significantly boost their maximum speed by increasing their stem length, without needing to exert more energy.

“Researchers in the bio-inspired robotics community need to pick and choose important features worth adopting from organisms over time,” said Richard Desatnik, a PhD candidate in the LeDuc lab and co-first author of the paper.

“Essentially, we have to decide on good locomotion strategies to get our robots moving. For example, would a starfish robot really need to use 5 limbs for locomotion or can we find a better strategy?” added Zach Patterson, CMU alumnus and co-first author.

Following the successful development of this Rhombot, the research team now hopes to use similar methods to study other extinct organisms, such as the first organism able to travel from sea to land – something which couldn’t be studied using traditional robot hardware, but which researchers say could be possible with Softbotics.

“Bringing a new life to something that existed nearly 500 million years ago is exciting in and of itself, but what really excites us about this breakthrough is how much we will be able to learn from it,” said LeDuc. “We aren’t just looking at fossils in the ground, we are trying to better understand life through working with amazing paleontologists.”

Reference: Desatnik R, Patterson ZJ, Gorzelak P, Zamora S, LeDuc P, Majidi C. Soft robotics informs how an early echinoderm moved. Proc Natl Acad Sci USA. 2023;120(46):e2306580120. doi: 10.1073/pnas.2306580120

This article is a rework of a press release issued by Carnegie Mellon University. Material has been edited for length and content.