The Incredible Shrinking Explorer: A Robotic Vine That Navigates Our Most Delicate Spaces

Researchers showed that the robot could navigate a model of human arteries. Photos: David Baillot/UC San Diego Jacobs School of Engineering

Researchers have developed a new kind of soft robotic skin that allows ultra-slender “vine robots,” only a few millimeters wide, to move through tight and delicate spaces with remarkable control. The breakthrough could open doors to minimally invasive medical procedures and inspections of confined, fragile environments such as jet engines.

The research was led by engineers at the University of California San Diego (UC San Diego). Their innovation lies in integrating a thin layer of actuators made from liquid crystal elastomer (LCE)—a material that contracts or expands in response to heat—into a flexible, soft skin that covers the robot. By precisely controlling both internal pressure and actuator temperature, the team achieved fine steering capabilities at an exceptionally small scale.

“Our work represents a step toward small, steerable, soft vine robots for applications in delicate and constrained environments,” said Tania K. Morimoto, associate professor of mechanical and aerospace engineering at UC San Diego and the paper’s corresponding author.

Mimicking Natural Growth

Vine robots move in a way that mimics the growth of climbing plants: they extend from the tip, turning their skin inside out to elongate without dragging their body along surfaces. This makes them ideal for navigating complex or sensitive spaces where traditional robots might cause damage.

However, shrinking these robots to millimeter scales has been challenging—particularly when it comes to steering. The UC San Diego team addressed this by embedding strategically placed LCE actuators into a soft, stretchable skin. Though only a few microns thick, these actuators are powerful enough to bend or twist the robot’s body on command.

READ ALSO: https://www.modernmechanics24.com/post/china-installs-key-component-in-fusion-reactor

To achieve this control, researchers embedded tiny, flexible heaters under the actuators to modulate temperature while developing a system to finely adjust internal pressure. The combination of heat and pressure control allowed the robot to make smooth, precise turns. The team found that using both inputs together produced the most reliable motion.

Navigating Arteries and Jet Engines

In experiments, the researchers tested their new robotic skin on vine robots 3 to 7 millimeters in diameter (about 0.1 to 0.3 inches) and roughly 25 centimeters long (10 inches). When actuated, the robots could bend by more than 100 degrees along their length and squeeze through openings half their diameter.

In one striking demonstration, the team guided the robot through a model of a human aorta and branching arteries, showing its potential for future medical applications such as navigating blood vessels or performing targeted drug delivery. In another test, the robot, fitted with a tiny camera, maneuvered through the interior of a jet engine model, demonstrating its promise for inspecting tight, hazardous environments without disassembly.

WATCH ALSO: https://www.modernmechanics24.com/post/tesla-self-driving-delivery-usa

“The soft skin developed in this work could also be adapted for other soft robotic systems—such as wearable haptic devices, soft grippers, and mobile soft robots,” said Sukjun Kim, a postdoctoral researcher in Morimoto’s lab.

The research team is now exploring ways to make the robot even smaller, add remote-control capabilities, and potentially enable autonomous navigation.