Researchers 3D Print Ceramic Structures Inspired by Sea Urchin Spines That Generate Electricity From Water Flow

Researchers at City University of Hong Kong (CityUHK) have made a breakthrough in smart materials: 3D printed ceramic structures inspired by sea urchin spines that can generate electricity from flowing water.

Nature as Inspiration

The discovery began when Professor Lu Jian's team noticed something remarkable about sea urchin spines. These naturally occurring porous ceramic structures possess an unexpected capability for mechanoelectrical perception — when water droplets or flowing water passes over the spine's surface, the gradient cellular structure instantaneously generates measurable voltage signals.

We observed that when a seawater droplet falls onto the spine's apex, the spine rotates rapidly within approximately one second, demonstrating a highly sensitive tactile response, the team noted in their research published in Nature. Subsequent voltage measurements revealed that droplet stimulation induces a transient potential of approximately 100 mV, while flowing water triggers stable electrical signals.

3D Printing Replicates and Enhances Natural Design

Using advanced 3D printing technology, the researchers were able to replicate and enhance this natural capability. By combining biomimetic structural design with additive manufacturing, they created ceramic structures that can convert mechanical energy from water flow into electrical signals.

The response speed is remarkably efficient — more than a thousand times faster than echinoderm visual perception. Notably, even in the absence of viable cellular tissue, the spines still produce the same voltage response, confirming that this perception capability comes from the structure itself, not biological processes.

Potential Applications

This breakthrough opens new avenues for next-generation smart sensing and underwater monitoring materials. Potential applications include:

• Underwater sensors: Self-powered monitoring systems for ocean conditions
• Smart marine infrastructure: Structures that can detect and report on water flow patterns
• Energy harvesting: Low-power generation from natural water movement
• Biomedical devices: Similar principles could be applied to body-worn sensors

Professor Lu Jian, Dean of the College of Engineering at CityUHK, noted that this research demonstrates how nature's designs can inspire more efficient engineered solutions. The sea urchin spine represents millions of years of evolutionary optimization, he said. Our 3D printing technology allows us to not just replicate but enhance these natural structures for human applications.