Over the last several decades, robotic systems have gotten more complex, advancing in terms of accuracy and capability. This is eventually allowing certain surgical and medical procedures to be partially automated.
Tsinghua University researchers have created a soft robotic tentacle that might be used to enhance the efficiency of several conventional medical operations. This tentacle, described in IEEE Transactions on Robotics, is controlled by their innovative control algorithm, in conjunction with the so-called active cooling for shape memory alloy, the robot’s actuation candidate.
“One day, a neurosurgeon doctor came to our lab and inquired about the prospect of producing a soft, controlled catheter for him to aid him in his neurosurgeries,” Huichan Zhao, one of the study’s researchers, told Tech Xplore. “He wants this soft catheter to be exceedingly safe for the environment and to be able to bend in various directions using a remote command. We created a soft robotic tentacle based on these specifications.”
Zhao and his colleagues’ original version of the robotic tentacle had two major flaws. The first is that it moved too slowly, and the second is that it was difficult to regulate its motions, especially in the face of known or unknown external disturbances.
To circumvent these constraints, the researchers developed a “multi-input-multi-output dual-channel” controller based on two control techniques for bending and swing motion, as well as an active cooling approach for SMA materials, to better regulate the motions of their robots. The primary goal of this controller is to increase the actuation speed of the robotic tentacle and enhance its controllability, which will allow for easier real-world application.
“Our tentacle is actuated by heating/cooling three Shape Memory Alloy (SMA) springs,” said Xin An, another researcher involved in the project. “These SMA springs would shrink/elongate during heating/cooling, causing the tentacle to bend in different ways at different angles. We employed a few cameras and markers mounted on the robotic tentacle to determine the tentacle’s real-time bending states, and a feedback controller to send orders to the SMAs and cause the tentacle to deform to a particular direction and bending angle.”
The energy density of the SMA springs driving the team’s robotic tentacle is substantial. As a consequence, the tentacle might be made lighter and more compact, which could be useful in certain medical applications. In a series of studies, the researchers remotely commanded their device to scan photos of a room using an inbuilt camera. They discovered that it produced highly promising results since it could conduct various bending actions both successfully and quickly.
“The smart materials effectively actuated the robotic tentacle, forming a relatively delicate, dexterous, and controlled manipulator,” Zhao added. “This implies that in the future, we may theoretically develop a robotic arm, catheter, or endoscope out of soft materials that operate similarly to stiff equivalents.”
While the researchers have only tested their robotic tentacle in the laboratory so far, they plan to someday test it in clinical settings, employing it to do actual operations. To that end, they are now attempting to develop the actuation, sensing, and control capabilities of their system so that it can aid surgeons in doing inside examinations without causing injury to the patient’s body.
“We now plan to connect onboard sensors to get our robotic tentacle’s real-time posture/shape,” An said. “Our sensing system might use an Inertial Measure Unit (IMU) or Fibber Bragg Gratings (FBG). If we can successfully achieve the posture/shape of our single tentacle module, we may join numerous module segments to create a longer, more dexterous soft manipulator.”
You might also be interested in reading, Enough clean water is filtered by solar-powered gel to suit daily demands
