Engineering Inspiration from the Ocean

International researchers visiting ASU BIOS explore how the structures of planktonic organisms inform a new generation of robots.  

Having access to a coastal research site at the Bermuda Institution of Ocean Sciences (ASU BIOS) and live samples made available through the Invertebrate Physiology Lab, visiting engineers and scientists are able to study one of nature’s most elegant and efficient swimmers, zooplankton. Their goal is not biological classification, but engineering transformation that turns the physics of soft-bodied marine life into the blueprint for the next generation of robots.

This interdisciplinary research blends experimental fluid mechanics, biological observation, and computational modeling. This work is led by Rajat Mittal, professor at the Department of Mechanical Engineering at John Hopkins and Arvind Santhanakrishnan, associate professor at School of Mechanical & Aerospace Engineering Oklahoma State University. Their work focuses on how soft-bodied marine organisms move through complex fluid environments and how those mechanisms might be replicated in engineered systems.

Rather than relying solely on equations or simulations, the team, with the support of Amy Maas and Leocadio Blanco Bercial, observes a diversity of live marine samples in controlled tanks at ASU BIOS. Using high-speed imaging and laser-based visualization techniques, they capture how zooplankton jellies and other similar organisms interact with surrounding water. The experimental setup often includes introducing fine tracer particles into the water and illuminating a thin plane with a laser sheet. This allows this group to reconstruct flow fields around tiny swimming organisms thus revealing how jets, vortices, and wake structures form.

As Santhanakrishnan describes the approach, the goal is to move beyond simple observation, “We take those recordings and digitize them and pick out how the particles move in the fluid.” This digitized motion becomes the foundation for quantitative analysis, enabling researchers to compute velocities, reconstruct flow structures, and compare biological motion against theoretical fluid models. At the heart of the effort is a question that bridges biology and mechanical engineering, namely how does evolution solve problems of movement in complex, unpredictable environments? Planktonic life has evolved over millions of years to navigate turbulence, conserve energy, and maintain stability without rigid skeletal structures or propeller-like appendages. Instead, they rely on flexible deformation and passive fluid interactions. Santhanakrishnan explains that by studying these natural “design experiments,” the team hopes to uncover principles that could improve human-built systems.

One of the most direct applications of this research is in robotics. Traditional autonomous underwater vehicles rely on rigid frames and propellers. While effective in controlled conditions, they struggle in turbulent, cluttered, or biologically sensitive environments. Soft-bodied organisms, by contrast, excel in precisely those conditions. They adapt their shape dynamically and respond passively to flow changes. The researchers see this as a model for a new class of engineering systems, specifically soft robots capable of adjusting their structure in response to environmental forces. 

Noel Rajive, a PhD student with Santhanakrishnan at the School of Mechanical & Aerospace Engineering Oklahoma State University, supports this work and added that “Conventional underwater drones use rigid structures and propellers, and they are not adaptable in turbulent environments.” The implication of our work is clear, he said, “instead of forcing machines to dominate fluid environments, future designs may learn to cooperate with them, significantly changing not only the design but also the application of robots.” 

The technical backbone of this work lies in kinematic reconstruction and particle image analysis. Multiple synchronized cameras capture motion in three dimensions, allowing these researchers to study both the organism and the surrounding flow field. This team also uses computational fluid dynamics models developed by Mittal, in parallel with experimental data. These models treat the organisms as deformable bodies interacting with viscous fluids. However, a key challenge is abstraction as many models simplify organisms into flat or idealized shapes. Santhanakrishnan noted the gap between model and reality, “We start with simplified assumptions but in reality, these marine creatures are complex three-dimensional structures.” This mismatch is precisely why experimental validation is essential. The laboratory data serves as ground truth for refining simulations.

Beyond movement, this research group is also interested in sensory biology, how simple organisms detect and respond to their environment with extreme speed and efficiency. This includes studying how microscopic organisms or jelly-like species perceive flow, pressure changes, and nearby objects through distributed sensory structures. Rajive said, “I’m trying to understand how their sensors are arranged and why that arrangement is effective.” These biological sensing strategies could inform the design of distributed sensor networks in robotics. Mittal emphasized the importance of field-based research environments that encourage collaboration between disciplines. Unlike large institutions where groups may remain siloed, ASU BIOS allows engineers, biologists, and modelers to interact daily. Mittal also highlights the logistical advantages of ASU BIOS as a site for interdisciplinary research, pointing out that access to live organisms, flexible experimental setups and efficiency in coordinating tests have been key drivers in our success. 

Looking ahead, this group believes robotics is shifting from rigid machines optimized for narrow tasks to flexible systems capable of adapting across conditions. The implications of this work extend far beyond marine biology. From underwater exploration to environmental monitoring and search-and-rescue robotics, the principles uncovered in these studies could reshape how machines move through fluid environments.

Nature has already solved many of the problems engineers are still struggling to define and broader investigations into motion, adaptability, and design are essential. Combining high-speed imaging, laser-based flow visualization, and computational modeling, this interdisciplinary group is breaking new ground on how to bridge the gap between biological evolution and engineered systems.