A team of biomechanical engineers and surgeons at McGill University has designed a miniature 3D-printing soft robot built to deliver hydrogels directly to the vocal cords during surgery. The innovation offers a new way to help patients recover their voices. The device features a 2.7 mm printhead, making it the smallest bioprinter reported to date.
Detailed in the Cell Press journal Device on October 29, the study describes how the technology tackles a long-standing challenge in vocal cord surgery. Once cysts, lesions, or cancers are removed, it is common for patients to develop fibrosis, stiffening the vocal folds and hindering the ability to speak. Hydrogels facilitate healing and can help maintain vocal fold flexibility, but the existing methods lack the precision needed to control injection in such a small and delicate space.
“Our device is designed not only for accuracy and printing quality but also for surgeon usability,” lead author, biomedical engineer Swen Groen, said in a press release. “Its compact and flexible design integrates with standard surgical workflows and provides real-time manual control in a restricted work environment.”
The soft robot’s design draws inspiration from the flexible movement of an elephant’s trunk, with a slender nozzle controlled by tendon-like cables. Surgeons can guide it manually under a surgical microscope, delivering hyaluronic acid-based hydrogel in lines as thin as 1.2 mm. The research team demonstrated the precision possible to achieve by reconstructing vocal fold shapes in simulated surgical models.
According to senior author Luc Mongeau, developing such a small and flexible device initially seemed out of reach. “I thought this would not be feasible at first – it seemed like an impossible challenge to make a flexible robot less than 3 mm in size,” he said.
After further testing, the team aims to ultimately bring the technology into clinical trials.
