A team of biomechanical engineers and surgeons has created a 3D-printing soft robot that could transform vocal cord surgery.
Designed to deliver hydrogels directly to damaged tissue, the device measures just 2.7 millimeters across, making it the smallest bioprinter ever reported.
The study details how this flexible, surgeon-controlled tool could help patients recover their voices after surgery by reconstructing delicate vocal tissues more accurately than ever before.
Vocal cord surgeries often leave patients with stiff, scarred vocal folds that make speaking difficult. Between 3 percent and 9 percent of people develop voice disorders due to cysts, growths, or cancers that require surgical removal.
Surgeons typically inject hydrogels to prevent scarring, but injections are hard to control in the narrow throat.
That’s where the McGill University team stepped in. “Our device is designed not only for accuracy and printing quality but also for surgeon usability,” said Swen Groen, a biomedical engineer and first author of the study.
“Its compact and flexible design integrates with standard surgical workflows and provides real-time manual control in a restricted work environment.”
The researchers aimed to create a miniature printer that could fit inside a patient’s throat without blocking the surgeon’s view. Existing bioprinters for the liver and colon were too bulky for such a delicate environment.
At first, even the scientists doubted it could be done. “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,” said senior author Luc Mongeau.
Elephant-inspired engineering
To achieve this breakthrough, the team drew inspiration from an unlikely source – the elephant’s trunk.
The printhead mimics its flexible, cable-controlled structure. A nozzle sits at the tip of a thin “trunk,” which connects to a control module mounted on a surgical microscope.
Illustration of minimally invasive in situ bioprinter. Credit – Device
The robot extrudes a hyaluronic acid-based hydrogel in fine, 1.2 mm lines. Surgeons can control it manually in real time across a 20 mm workspace, achieving precise, repeatable movements.
“Part of what makes this device so impressive is that it behaves predictably, even though it’s essentially a garden hose,” said co-author Audrey Sedal. “And if you’ve ever seen a garden hose, you know that when you start running water through it, it goes crazy.”
The researchers tested the system by manually “drawing” shapes such as spirals, hearts, and letters. Then, they used it to deliver hydrogels to synthetic vocal folds used in surgical training.
The robot accurately reconstructed the folds’ geometry, replicating real tissue defects caused by lesion removal or partial reconstruction.
Towards clinical application
Currently, surgeons operate the device manually, but the team plans to add semi-autonomous features. “We’re trying to translate this into the clinic,” said Mongeau.
“The next step is testing these hydrogels in animals, and hopefully that will lead us to clinical trials in humans to test the accuracy, usability, and clinical outcomes of the bioprinter and hydrogel.”
If successful, this palm-sized robot could mark a new chapter in microsurgery – one where lost voices are rebuilt, one layer at a time.
Aamir Khollam Aamir is a seasoned tech journalist with experience at Exhibit Magazine, Republic World, and PR Newswire. With a deep love for all things tech and science, he has spent years decoding the latest innovations and exploring how they shape industries, lifestyles, and the future of humanity.