A research team at the University of Toronto has unveiled a groundbreaking set of miniature, magnetically powered surgical tools that could significantly improve the way brain surgeries are performed. These tools, just 3 millimeters (0.1 inch) in diameter, are designed to carry out delicate tasks such as gripping, cutting, and pulling tissue — all without the need for traditional motors. Instead, they are guided using external magnetic fields, making them a potential game-changer for keyhole brain surgery.
This innovation promises faster recovery times, less pain, and minimal scarring, offering a safer and less invasive alternative to conventional brain surgery techniques.
The development was a collaboration between engineers at the University of Toronto and medical researchers from The Hospital for Sick Children’s Wilfred and Joyce Posluns Centre for Image Guided Innovation and Therapeutic Intervention.
“In the past couple of decades, there has been this huge explosion of robotic tools that enable minimally invasive surgery,” said Dr. Eric Diller, professor of mechanical engineering and study coauthor. “But making those tools smaller and more precise has always been a challenge.”
Traditionally, surgical robots mimic the human hand using cable-driven systems, like tendons pulling fingers. However, these systems break down at micro scales due to increased friction and decreased reliability. The new approach ditches cables altogether, using magnetically responsive materials to create motion.
The system consists of two core parts:
- Tiny surgical instruments – including a gripper, forceps, and a scalpel.
- An electromagnetic coil table – which generates magnetic fields to control tool movement.
During a procedure, the patient’s head would rest over the coil table while the tools are inserted through a small incision in the skull. Surgeons manipulate the tools by adjusting the current running through the coils, prompting the instruments to move and perform specific tasks — all without direct contact.
“By using magnetic fields, we can remotely control these tools with precision, even in the confined space of the human brain,” Diller noted.
To test the tools, the team created a life-sized silicone brain model and used tofu and raspberries to mimic brain tissue. Tofu represented the corpus callosum — a structure of soft tissue — ideal for testing the cutting capabilities of the scalpel. Raspberries, with their soft texture, were used for gripping exercises, simulating the removal of diseased tissue.
Dr. Changyan He, a former postdoctoral fellow involved in the research, explained, “The tofu has a consistency very similar to brain tissue, making it ideal for replicating real surgical conditions.”
The results were impressive:
- The magnetic scalpel made consistent, ultra-precise cuts measuring 0.3 to 0.4 millimeters — far narrower than those made with traditional hand tools (which ranged from 0.6 to 2.1 millimeters).
- The grippers achieved a 76% success rate in removing the targeted tissue without causing damage.
Similar performance was observed in tests involving animal models, suggesting the tools are viable for further clinical development.
With traditional brain surgery often involving large incisions, extended recovery times, and potential complications, this magnetic toolset opens the door to a less invasive and more controlled approach.
The team hopes that with continued testing and refinement, these tools could soon enter clinical trials and eventually become part of standard surgical practice — particularly for conditions requiring delicate navigation of brain tissue.
“This work shows what’s possible when engineering and medicine come together,” said Diller. “Our ultimate goal is to make brain surgery safer, faster, and more precise.”
As this technology advances, it could also pave the way for remote-controlled microsurgery and other minimally invasive procedures far beyond neurology.
By Impact Lab
