TECH + Engineers at the University of California, San Diego (UC San Diego) have unveiled a groundbreaking soft “vine” robot capable of navigating highly constrained and delicate spaces including models of human arteries and the inner chambers of jet engines by growing from its tip and steering precisely.
The core innovation involves integrating a thin robotic skin embedded with actuators composed of liquid-crystal elastomer (LCE). This skin is wrapped around a soft body that everts turns inside-out at the tip allowing the robot to extend forward without dragging against surrounding surfaces. By controlling internal pressure and selectively heating the LCE actuators, the robot can both stiffen and bend, enabling it to twist through tight curves and squeeze into gaps as narrow as half its own diameter.
In laboratory demonstrations, machines between 3 and 7 millimetres in diameter and about 25 centimetres in length managed turns exceeding 100 degrees, traversed a model of a human aorta, and threaded into the interior of a jet-engine mock-up. One researcher said the advance “represents a step toward small, steerable, soft vine robots for applications in delicate and constrained environments.”
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Traditional soft-robot designs often struggle with steering at such small scales because actuators and mechanisms become bulky relative to the body. The UCSD team overcame this by using the ultra-thin LCE layer and heaters embedded beneath it, so the robot can change curvature by activating temperature zones while pressure maintains shape. They found that using pressure control and heater actuation together provided superior steering precision and responsiveness.
The researchers envision a wide range of applications: in medicine, the vine robot could navigate vascular systems for minimally invasive diagnostics or treatment; in aerospace or industrial inspection, it could venture into confined cavities or tight engine passages inaccessible to conventional tools. They noted that this skin technique could also be adapted for soft grippers, wearable haptic devices, or mobile limbs in future robot systems.
While the prototype is promising, scaling it for real-world deployment still involves challenges. Mapping human anatomical variation, ensuring robustness under long-term use, and developing reliable autonomous control are next steps. But the work highlights a significant leap: robots not just stiff or rigid, but able to behave like flexible vines—growing, steering, and adapting to the environment in real time.
