Our world’s deep oceans are some of the least explored places on the planet, but a new type of soft robot recently tested in the Mariana Trench is leading the way in changing this. Inspired by deep-sea creatures that thrive at large depths, researchers have engineered a soft robot based on the structure of the deep-sea snailfish.
Extremely high pressures in the deep sea makes exploration of these areas particularly difficult, with robots requiring strong, rigid vessels and complex pressure-compensation systems to protect their electrical components from damage. However, by embedding delicate electronics in soft silicone, the engineers have removed the need for rigid, pressure-resistant casing.
The self-powered robot has a fish-like body shape and two side wings which ‘flap’ to power movement. These side wings are powered by two material ‘muscles’ which ‘contract’ when a current is applied, converting electrical energy into mechanical movement.
The positioning of electrical components within the robot was also inspired by the snailfish; with the components being spaced out within the vessel rather than packed together with the circuit board, as is typically done. This internal layout is based specifically on the bones in the skull of the snailfish and works to reduce stress at the interfaces between electronic components. An added bonus of this technique is that it is also a much cheaper way of protecting the electronics in deep-sea robots than other traditional methods.
The soft robot was given plenty of time to practice its swimming technique before venturing out into the Mariana Trench. Engineers first tested it in a laboratory water chamber, a lake of 70m depth and then the South China Sea at a depth of 3,200m. On its maiden voyage into the Mariana Trench however, our soft robot was not alone and was connected to a conventional deep-sea device for additional support and to take pictures.
There is still some more work to be done before soft robots such as this one will be able to explore our most uncharted depths. The robot could be easily swept away by underwater currents and would need to be able to survive large underwater disturbances in order to be a successful explorer. On top of this, our soft robot is no Michael Phelps, recording a slower swimming speed than other previously tested underwater robots.
Despite this, the work of these engineers continues to push the boundaries of the capabilities of soft-robots for underwater exploration. A successful generation of soft robots could lead to huge advances for numerous marine sciences, from marine biology and enhanced specimen collecting, to better ocean clean-up and species monitoring. Moreover, these robots could pave the way into exploration of our vast unchartered waters.
