A group of scientists in Italy have taken their inspiration from the octopus, creating a robotic arm that can bend, squeeze, and stretch through even cluttered environments. The device was created specifically for surgeons who need to access confined or remote areas of the body more easily. The results were presented this week in the journal IOP Publishing's journal Bioinspiration and Biomimetics.
The manipulability of the arm also allows practitioners to work with soft organs without damaging them. The arm may be able to allow doctors to operate through fewer incisions, with fewer instruments, and more safely. The arm can work either as a flexible, bending tool or as a rigid instrument.
This set of advantages was inspired by the eight arms of the octopus. Highly flexible, they lack rigid skeletal support and therefore can adapt to their surroundings easily by just bending in any direction, changing their length, or twisting at any point along the arm. An octopus is also capable of making its arms rigid for better control during interactions with objects.
The researchers, from the Sant'Anna School of Advanced Studies in Italy, achieved the same qualities in the robotic arm by interconnecting identical pieces to construct the larger device. Each individual component has three cylindrical chambers inside it which can be inflated. The module stretch and bend in many directions as the three chambers are inflated and deflated in alternating combinations.
These qualities are refined with the use of granular media wrapped in flexible membranes inside the modules. The module's density and rigidity change as a vacuum is applied.
"The human body represents a highly challenging and non-structured environment, where the capabilities of the octopus can provide several advantages with respect to traditional surgical tools" lead author of the new study, Dr. Tommaso Ranzani says.
"Generally, the octopus has no rigid structures and can thus adapt the shape of its body to its environment. Taking advantage of the lack of rigid skeletal support, the eight highly flexible and long arms can twist, change their length, or bend in any direction at any point along the arm."
The team's results show that the arm can stretch to up to 62 percent of its initial length and bend to angles of up to 255 degrees. The stiffening mechanism was able to increase rigidity from 60 percent up to 200 percent.
"Traditional surgical tasks often require the use of multiple specialized instruments such as graspers, retractors, vision systems and dissectors, to carry out a single procedure," Ranzani says.
"We believe our device is the first step to creating an instrument that is able to perform all of these tasks, as well as reach remote areas of the body and safely support organs around the target site."