Inspired by nature.

With spring eagerly anticipated by those of us residing in the northern hemisphere, our thoughts often turn to nature and the return of color into our gardens and greenspaces. While the vivacity and vibrancy of the visual aspects of nature are appreciated by many, it is also incredible to contemplate just how many scientific discoveries have been influenced by nature’s properties on the microscopic scale.

There was a recent review article released on functional surface microstructures. It was a good reminder that the design of intricate surface patterns to create useful functionalities have commonly been inspired from investigations into biological surfaces. For example, the leaves of sacred lotus plants and their ability to repel water, also known as super-hydrophobicity, helped drive the exploration of wetting properties of a surface and the self-cleaning mechanism. Aquatic springtails and fire ants take advantage of capillary forces to assemble into colonies, enhancing buoyancy and reducing the risk of sinking. On a surface, these capillary forces can be harnessed to induce or enhance mobility and direct motion of a liquid droplet.

Biological surfaces not only repel but also have adhesive properties, with the gecko being the most celebrated example. The investigations of the gecko footpads show them to have an unusually hairy structure and it was later discovered that their adhesion is predominantly due to van der Waals interactions, although capillarity forces and electrostatic forces also participate.

The authors summarize their findings with the following statement: “The understanding of microstructure effects is, at the present state, advanced but far from complete. Manipulation of wetting behavior has become a rich branch of modern applied physics, with far reaching implications, e.g. for water management, cooling systems, wind turbines and oil exploration and extraction.”

Although not without their shortcomings, bioinspired materials continue to fascinate on both an engineering and chemistry front. Advances in surface analytical instruments, such as Rigaku’s thin film analyzers and X-ray microscopes, have made research into this area more accessible.