TechTheDay

Clams: you probably find them boring. You probably think that these shelled aquatic animals are the sedentary type, incapable of quick locomotion and moving just like the way a snail does. Well, if you have not seen clams in real action,  prepare to realize how gravely mistaken you are. There are some clams that can propel themselves to “swim” around in the water. Additionally, clams are packed with enough power to be able to dig their way for up to 500 meters into the the sand.

The Atlantic jackknife clam (Ensis directus) is one example of a highly capable clam. It can “swim” and burrow into wet sand very quickly. It is an impressively skilled mollusk that it inspired engineers at the Massachusetts Institute of Technology (MIT) to create a robotic clam capable of emulating their movements. MIT has been working on robots that derive inspiration from the capabilities of clams. They’ve been developing the RoboClam project since 2008. The main goal back then was to develop smart anchoring technologies.

Recently, MIT announced the results of some years of research and development work on the robotic clam project. In a report published in the journal Bioinspiration and Biomimetics, MIT engineers provided details on how the RoboClam works. The engineers involved were Amos Winter, an MIT mechanical engineering professor, and Anette Hosoi, a mechanical engineering and applied mathematics professor also at MIT.

Highlights of the report are as follows:

Mechanism

As mentioned, the RoboClam is designed to mimic the quick movements and burrowing abilities  of the Atlantic jackknife clam (also known as the Atlantic razor clam). The RoboClam is similarly composed of a two-part mechanical shell that can be spread open like an accordion, emulating the physical movements or actions a real clam does. These actions allows the robot to “liquify” the sand around it and create a mini quicksand through which it can move forward more easily. Water is also injected into the body of the robotic clam to facilitate forward movement.

Inspiration for the RoboClam Concept

Professors Winter and Hosoi thought of developing the RoboClam while looking for energy efficient methods of anchoring underwater vessels. According to Winter, “You might be operating these vehicles in a current, and need them to be stationary – for example, to monitor a biological situation, or for military purposes.” He adds that it will always be great to avoid wasting energy on continuously spinning propellers to maintain stability while trying to be stationary or still underground. Being able to deploy a reliable robot-aided anchor will indeed be very useful.

The razor clam was deemed as an excellent model for a novel anchor because of its exemplary efficiency as a digger. It is relatively fast, moving about a centimeter per second, and requires minimal energy to move forward. Moreover, in terms of anchoring efficiency, Winter claims that the “razor clams beat everything, including the best anchors, by at least a factor of 10.” They can dig deep and are known for having their high anchoring force.

Applications

There are two major applications associated with the development of the RoboClam. One is for power-efficient anchoring and another is for military purposes.

The RoboClam can be used to anchor buoys or underwater observation vehicles that need to stay in one area to do longer observations. In this application, the advantage of having a robotic clam doing the anchoring is mainly on energy efficiency. Underwater vehicles that have to be stationary for some time can benefit from anchoring as it allows them to stand still without the need to continuously use their propellers or other power-consuming thrusting mechanisms.

Additionally, RoboClams can reposition themselves whenever necessary. They are also easier to recover since they can more easily get themselves out of the sea floor. They are expected to be helpful for robotic submarines that are routinely relocated to undertake research or data gathering.

For military application, on the other hand, the RoboClam can be used to get rid of mines or to dig into the sea bed to install mines. There are many other possible military uses of the device. Further studies and developments, however, will be needed to explore these possibilities.

Nature, indeed, is a good model for technology. It demonstrates how things can be efficiently achieved. It shows how simple movements and mechanisms can bring about technological creations that can be very useful. Though not as advanced as the AI-integrating bionic tentacle developed by German engineers, the RoboClam is still a great invention that exemplifies nature’s influence on technology.