Mechanical engineering students develop flexible robot to improve lung exams | Paul M. Rady Mechanical Engineering

Soft Robot Team for Surgical Interventions

  • Maxwell Anderson – Logistics Manager
  • Sean Dunkelman – System Engineer
  • Christopher Gonzalez – Software Engineer
  • Brady King – Electromechanical Engineer
  • Isaac Martinez – CAD Engineer
  • Brad Nam – Manufacturing Engineer
  • Caitlyn Robinson – Test Engineer
  • Renée Schnettler – Project Manager
  • William Wang – Electromechanical Engineer
  • William Watkins – Chief Financial Officer

Seniors from the Department of Mechanical Engineering at the University of Colorado Boulder are designing a new flexible robot to improve doctors’ ability to examine the deepest part of a patient’s lung.

Currently, there is only one system that can reach deep into the lungs – a rigid catheter that could potentially cause inflammation. The team of mechanical engineering students is working with medical device company Medtronic to make the tip of this catheter more flexible.

“Our customer is hoping to reduce the strain on the body by replacing the tip of the device with something very flexible and soft, especially compared to the materials used today,” said Maxwell Anderson, logistics manager for the ‘team. “We are trying to create a soft robot for the tip that will allow the doctor to have more control over the tip and make it less abrasive to the patient.”

The students approach this project as part of the department’s Senior Design course. They spent the college year researching, designing, molding, and testing various iterations of their soft robot prototype.

An iterative design process

Renée Schnettler and Maxwell Anderson show how the flexible robot bends with air pressure.

control test
Sean Dunkelsman, William Wang and Brady King test the team control system.

The team’s basic design is a hollow silicone tube with bubbles on the outside. The bubbles expand when the soft robot is inflated with air pressure, causing the tube to bend. The students explained that the flexing motion is the key aspect of their design, as it is this configuration that allows the flexible robot to move through the deepest parts of the lung.

“The catheter still does most of the work during the procedure, and then the doctors control the soft robot at the very end to just move the tip,” said Renée Schnettler, the team’s project leader. “It can latch on to different areas and allow doctors to send a needle there to take a sample of any lung tissue they’re studying.”

The team said they are constantly making new prototypes for testing. The R&D process has resulted in 55 prototypes since fall 2021.

“A lot of what we’ve done builds on our base design,” said Isaac Martinez, the team’s CAD engineer. “We observe how this prototype behaved and try to change some dimensions. It would be an iteration. Then we change another aspect, like the number of bubbles, and it becomes a second iteration. We tried to put this image together complete from many different prototypes.

Every change in the prototype design was purposeful and intentional. This includes adjustments to the soft robot control system.

“Our control team spent a lot of time trying to figure out how we can tell where the tip of the robot is,” said electromechanical engineer William Wang. “We have tried to improve our control systems to achieve the desired positions, but each iteration of our prototype behaves slightly differently depending on the properties of the material. We have tried to find more robust techniques to control them all.