On the face of it, corn plants seem to serve a pretty simple purpose: to produce corn; but when we look more closely, they can provide us with a blueprint for building lightweight and incredibly strong structures

Corn is a tall, strong plant that can endure all sorts of physical stressors. Hail, storms, pruning, thinning, and more – the plants still thrive despite the severe physical strains often placed on them. 

New research from the Impact Dynamics group at UNSW Canberra shows that the structural make-up of cornstalks can teach us a lot about building impact-resilient and lightweight engineering structures. 

According to lead researcher and UNSW Canberra PhD candidate, Shakib Hyder Siddique, cornstalks are a natural engineering phenomenon.

"Cornstalks are biologically lightweight materials with a superior stiffness-to-mass ratio compared to metallic materials such as steel and aluminium," Shakib said.

"In other words, cornstalks are light, but also very strong." 

A cross-section of a cornstalk comprises of vascular bundles and medullary core (representing a porous tubular and foam structure) that carry water and nutrients throughout the plant.

The combination of the vascular bundles and foam matrix significantly lowers the mass of the structure while maintaining the superior load-bearing strength of the cornstalk. 

Cornstalks have a unique porous structural make-up, which allow these plants to withstand all kinds of external forces. Source: Shakib Hyder Siddique

“These structural characteristics of a cornstalk can then be mimicked to design thin-walled structures that are resilient to load,” Shakib said.

Shakib explored the structural make-up of cornstalks, testing their strength and ability to withstand compressive force. That is, for the first time, researchers were identifying whether the cornstalk-inspired design could absorb mechanical pressure.

Through 3D printed models and numerical simulation, the researchers found that cornstalk structures had significantly higher energy-absorbing capability compared to porous foam (18% higher), honeycomb structures (79% higher), and lattice structures (74% higher). 

Cornstalk-inspired design was shown to be superior in its ability to withstand a load. Given the porous structure of cornstalks, the design provides a unique solution for building lightweight and strong structures. 

“Due to the porous architecture of the cornstalk-inspired design, and its significant ability to take on high loading, these lightweight structures can have unique applications in everyday life," Shakib said. 

“For example, in the case of electric vehicles, reducing the weight of the vehicle potentially increases the driving range powered by batteries. Some examples of vehicle parts that contribute to weight are; a diesel piston, a fluid pump, and a racing car cylinder head,” Shakib said. 

“In all cases, cornstalk-inspired structures significantly reduce mass, while still fulfilling mechanical performance requirements.”

Shakib is currently expanding on this research, exploring the impact-resistance capability of cornstalk-inspired structures in response to impact at high speed. While still in its early stages, the research has significant implications for real-world applications of lightweight structures. 

So if you happen to be wandering through a field of corn plants, you may be able to appreciate the deep building blocks of the plant that allow it to thrive under all sorts of conditions.

The research team comprises members of the Impact Dynamics group, including UNSW Canberra Ph.D. candidate Shakib Hyder Siddique, Professor Paul Hazell, Dr. Hongxu Wang, Dr. Juan Escobedo, and Dr Ali Ameri. The peer-reviewed paper was published in Biomimetics: https://doi.org/10.3390/biomimetics8010092 

UNSW Canberra Ph.D. candidate, Shakib Hyder Siddique, is part of the Impact Dynamics group, and is interested in using nature to design impact-resistant structures. Source: UNSW Canberra