A soft robot inserted through a small hole in the skull can deploy six legs packed with sensors on the surface of the brain. A version of this soft robot has been successfully tested on a miniature pig and could be expanded for human testing in the future.
The concept offers a less invasive approach to placing electrodes on the surface of the brain compared to the traditional method, in which surgeons drill a hole in the skull the size of the fully extended device. If it proves safe and effective in humans, it could eventually help monitor and even treat people experiencing seizures or other neurological disorders.
“There’s actually a really large surface area that can be reached without doing a large craniotomy,” he says. Stephanie Lacour at the Swiss Federal Institute of Technology in Lausanne.
The soft robot is 2 centimeters long and its legs are mainly made of flexible silicone polymer. The legs resemble curved flower petals that spiral around the central body and, when fully extended, cover a diameter of 4 centimeters. Each paw contains electrodes to monitor brain activity.
The legs could be lengthened by as much as 8 or 10 centimeters in future prototypes without having to increase the size of the hole cut in the skull, he says. sukho song at the Swiss Federal Laboratories for Materials Science and Technology and part of the research team.
When tucked in, the legs are sleeve-like with the cuff pulled back toward the shoulder, like it’s inside out. deploy, the legs fill with fluid, which pushes them out.
The robot was tested on a model of the brain made of plastic and hydrogel. But the researchers also showed how they could deploy a single, straight, 15-millimeter-long robotic leg into the brain of a Göttingen mini-pig. In a demonstration inside the live animal, the soft robot’s electrodes recorded patterns of brain activity as the researchers electrically stimulated the minipig’s snout.
Implementing a soft robot on the surface of the brain is challenging because there is virtually no gap between the human brain and the skull: on average, it’s a gap of just 1 millimeter, Lacour says. The researchers designed the robot’s legs to expand smoothly and avoid putting too much pressure on the brain.
Strain sensors built into each leg transmit information about when the robot’s legs are fully deployed, without the need for additional cameras or external sensors. “Their innovative use of strain sensors…has the potential to reduce the need for postoperative imaging and shorten the time spent in the operating room,” he says. damian barone at Cambridge University.
Once the brain-monitoring task is complete, the robot’s legs are deflated so they can be easily removed by a surgeon. The researchers plan to eventually scale up the soft robot for human testing through a startup company called Neurosoft Bioelectronics.
