A multidisciplinary team of researchers from Case Western Reserve University, in the USA, has built a biohybrid robot that combines oral muscle tissue from a sea slug and two “arms” made from a flexible 3D-printed polymer . When an electrical stimulus is applied, the organic part contracts and relaxes and causes the artificial limbs that cover it to move, more or less like a sea turtle would move along a beach to spawn.
“We are building a living machine, a biohybrid robot that is not entirely organic,” says Victoria Webster, a mechanical engineer from the aforementioned institution, who has coordinated this initiative, in which biologists to experts in bionics have participated. These focused on the species Aplysia californica , a characteristic mollusk of the Pacific coast of Mexico and the United States, which has a great capacity to adapt to different environments.
“One of the main problems that we find in traditional robotics is that the actuators, that is, the units that allow a device to move, tend to be rigid,” says Webster. “Muscle cells form soft structures much more efficient and safe than purely mechanical systems; in addition, they carry, so to speak, their own fuel, nutrients that they take from the environment ”, indicates this expert.
In the first tests with this biohybrid robot, which is about 5 centimeters long, the scientists managed to make it move about 4 millimeters per minute. However, they ensure that their movements will be much more fluid in the future. To do this, they plan to incorporate the animal’s own ganglia into the device. In this way, they could also use chemical stimuli to induce muscle movement. “Thanks to the nerve cells, they will be able to carry out more complex tasks, even more so than if we used a control system devised by ourselves; weaving can also learn, ”says Webster.
Now, this researcher and her collaborators are working on a completely organic version of their robot, whose external structure would be made from the collagen of the sea slug itself , which would function as a kind of scaffolding. The idea is that these biomachines carry out long-term underwater missions that exceed the capacities of conventional robot batteries, such as detecting the source of a toxic spill or locating black boxes.
Image: Victoria Webster
