AI & ML Nature Is Weird

A soft growing robot can turn parts of its own body into hard bone to lift heavy tools.

April 20, 2026

Original Paper

A Reconfigurable Pneumatic Joint Enabling Localized Selective Stiffening and Shape Locking in Vine-Inspired Robots

Ayodele James Oyejide, Ustaz A. Yaqub, Samir Erturk, Eray A. Baran, Fabio Stroppa

arXiv · 2604.15907

The Takeaway

This vine-inspired robot uses a pneumatic joint system to selectively stiffen parts of its structure while it continues to grow. It mimics how plants harden their stems to support weight or resist the wind. Before this, growing robots were too floppy to perform real work like lifting objects or pushing buttons. The robot can now snake through a narrow pipe and then lock its shape to become a stable platform for sensors. This breakthrough turns soft robots from fragile explorers into powerful tools for search and rescue operations.

From the abstract

Vine-inspired robots achieve large workspace coverage through tip eversion, enabling safe navigation in confined and cluttered environments. However, their deployment in free space is fundamentally limited by low axial stiffness, poor load-bearing capacity, and the inability to retain shape during and after steering. In this work, we propose a reconfigurable pneumatic joint (RPJ) architecture that introduces discrete, pressure-tunable stiffness along the robot body without compromising continuou