Microstructure in Seed Coats May Result in Strong, More Flexible Materials


The University of New Hampshire where the research about seeds that can enhance flexiblility and strength of a material were conducted. / Photo by: Millyard800 via Wikimedia Commons


Inspired by nature, researchers at the University of New Hampshire found aspects of seed coats that can be applied to the development of strong, yet flexible materials.

The team took their inspiration from a seed coat, a protective part of a plant seed that shields it from different hazards. When they looked into the microstructures of the seed coat, they noticed that the building blocks were epidermal cells and had been star-shaped. Further examination exposed that the star-shaped cells formed a compact and tiled exterior, giving it the ability to protect the seed.

“By learning from nature it may be possible to tailor the geometry and create the architecture for a smart material that can be programmed to amplify the strength and toughness but also be flexible and have many different applications,” stated Yaning Li, an associate professor of mechanical engineering at UNH.

The pattern of the cells defends the seed from numerous dangers such as mechanical damage, drought, freezing, water damage, and even bacterial infection. To understand how the pattern does it, the researchers created design prototypes and manufactured them using multi-material 3D printing. The models were also analyzed using finite element simulations and mechanical experiments.

After analyzing the simulations and reviewing other data, they discovered that the coat’s structure called sutural tessellations play a vital role in determining the mechanical response. When the structure had wavier form, more applied loads could be carried to the hard phase of the coat, which translated to an increase in overall strength and toughness.

The researchers concluded that the principles of the seed coat’s microstructure showed a promising approach to improve the mechanical performance of synthetic materials. They believe that several applications can utilize the structural concept of the seed coat, such as new graded composites, energy absorption and dissipation, and new smart materials with a tougher exterior.