Researchers at Case Western Reserve University have combined tissues from a sea slug with flexible 3-D printed components to build “biohybrid” robots that crawl like sea turtles on the beach.
A muscle from the slug’s mouth provides the movement, which is currently controlled by an external electrical field. However, future iterations of the device will include ganglia, bundles of neurons and nerves that normally conduct signals to the muscle as the slug feeds, as an organic controller.
The researchers also manipulated collagen from the slug’s skin to build an organic scaffold to be tested in new versions of the robot.
In the future, swarms of biohybrid robots could be released for such tasks as locating the source of a toxic leak in a pond that would send animals fleeing. Or they could search the ocean floor for a black box flight data recorder, a potentially long process that may leave current robots stilled with dead batteries.
The researchers chose the sea slug because the animal is durable down to its cells, withstanding substantial changes in temperature, salinity and more as Pacific Ocean tides shift its environment between deep water and shallow pools. Compared to mammal and bird muscles, which require strictly controlled environments to operate, the slug’s are much more adaptable.
Muscle cells are compliant and also carry their own fuel source–nutrients in the medium around them. Because they’re soft, they’re safer for operations than nuts-and-bolts actuators and have a much higher power-to-weight ratio.
If completely organic robots prove workable, a swarm released at sea or in a pond or a remote piece of land, won’t be much of a worry if they can’t be recovered. They’re likely to be inexpensive and won’t pollute the location with metals and battery chemicals but be eaten or degrade into compost.
