In this blog post, we’ll explore the evolution of biomimicry—the process of creating new technologies by mimicking nature’s structures, functions, and the principles behind natural phenomena—and examine some representative examples.
Biomimicry: Learning from Nature
There is nothing new under the sun. This saying perfectly captures the essence of biomimicry. Humans have invented countless things over the centuries. But did all these inventions originate solely within the human mind? It is a well-known story that the Wright brothers, who achieved the first powered flight in 1903, observed the flight of birds and conceived the design for their aircraft. In this way, the development of technology based on the forms of nature and living organisms—such as animals, plants, and insects—is called biomimicry. Just as the Renaissance painter Leonardo da Vinci observed birds and drew blueprints for flying machines, biomimicry is not a field that has suddenly emerged in recent times. It can be said that the origins of biomimicry lie in humanity’s continuous process of learning from and emulating the diverse aspects of nature for survival since the dawn of humankind.
From Nature’s Appearance to Function and Principles
In the past, most innovations involved observing and imitating nature’s outward appearance—for example, developing hook-and-loop fasteners by studying the shape of seeds with hooks, or conceiving of airplanes by observing birds. A prime example is the Swiss inventor Georges de Mestral, who observed how hook-shaped seeds attach to clothing or animal fur and used this insight to develop a hook-and-loop fastening system. As time went on, researchers began to focus not only on the outward appearance of nature but also on its functional aspects.
Bats emit sounds and analyze the echoes to determine the location of nearby objects or obstacles. Research into this echolocation inspired the development of sensors that utilize acoustic information and advancements in ultrasound technology, and it also served as a starting point for understanding detection technologies like radar by drawing on nature’s sensory systems. Recently, this approach has evolved beyond simply imitating outward appearances or functions to understanding the underlying principles of natural phenomena and applying them to other fields. A prime example of this is research on the soles of geckos’ feet.
The Principle of Adhesion Discovered in Gecko Feet
Have you ever seen the scene in the movie ‘Mission: Impossible 4’ where Tom Cruise climbs a building wall while wearing special gloves? Some people who watched that scene may have wished such gloves actually existed. Using biomimetic technology inspired by the gecko’s feet, it might be possible to actually create devices like these gloves. Geckos can cling to walls or ceilings without secreting any adhesive; the secret lies in the dense array of microscopic hairs on their feet and the nanometer-scale structures at their tips.
Geckos can walk while clinging to walls or ceilings. However, their feet do not secrete any special adhesive substance to support their bodies. So how do geckos keep their feet attached to walls or ceilings under normal circumstances, and how are they able to detach their feet from these surfaces without exerting much force when they move? The principle behind this can be understood by examining a gecko’s foot. A gecko’s foot is densely covered with microscopic hairs. Each of the gecko’s toes has numerous microscopic hairs, and when the tips of these hairs come into very close contact with the surface of a wall, van der Waals forces act between the molecules. Although each individual force is very weak, because they act simultaneously across countless microvillous hairs, they collectively generate a strong adhesive force.
It is not easy to uniformly arrange millions of microstructures within a small area using conventional mechanical methods alone. Since the length of the microvillous hairs is as small as the micrometer or nanometer scale, materials such as polymers and microfabrication technologies are required. In fact, researchers—including a team from Stanford University—have developed directional adhesive pads that mimic the gecko’s adhesion mechanism and applied them to robotic feet to study technologies for moving on vertical, inclined, and even inverted surfaces. In this way, biomimetic technology that mimics the gecko’s movement is being utilized to advance robotic locomotion and adhesion technologies.
How far has biomimetic technology advanced?
Recently, in addition to research on gecko feet, studies are underway to create biomimetic nano-sponges using red blood cell membranes to remove toxins from the bloodstream. Toxins—such as those found in some snake venoms or bacterial toxins—that damage cells by creating holes in cell membranes can have fatal effects on the human body. However, when biomimetic nano-sponges enclosed in red blood cell membranes are present in the bloodstream, toxins target the nano-sponges instead of actual blood cells and can be absorbed by them. These toxin-absorbing nano-sponges work by preventing toxins from attacking healthy cells, thereby reducing toxicity. Initial studies using mice confirmed that this approach reduces the toxicity of specific toxins and increases survival rates. Subsequent studies continued to explore the potential of these red blood cell membrane-based nanosponges against various bacterial toxins.
Additionally, research was conducted using biomimetic technology to process graphene—once hailed as a “dream material”—into intricate shapes by using DNA itself as a template. Because DNA has the unique property of enabling the creation of nanostructures in desired shapes, it can be used as a template to form nanometer-scale patterns on graphene. The research team coated DNA nanostructures with metal and used them to create patterns of the desired shape on graphene; it was suggested that this technology could be utilized to fabricate graphene-based nanoelectronic circuits and various nanostructures. Additionally, research was conducted to grow graphite-based nanoribbons with widths less than 10 nanometers using DNA as a template.
Biomimicry is not only helpful in researching new technologies but can also be used to complement or replace existing technologies. One such example is research aimed at developing surgical patches that are stronger and more precise than conventional surgical staplers by mimicking the way parasites in fish intestines burrow into host tissue. In this way, by closely observing the structures and functions of organisms found in nature, we can discover new methods to overcome the limitations of existing technologies.
Is nature the oldest inventor?
Even today, many engineers around the world are conducting research by utilizing the structures and materials found in nature, as well as the principles of natural phenomena. While the history of human invention spans tens of thousands of years, nature has been creating diverse structures and functions for billions of years through countless trials, errors, and evolutionary processes. Humans can observe and study these products of nature—accumulated over such a long period—and apply them to new technologies. However, the role of engineers is not merely to imitate the structures and functions created by nature, but to accurately understand their underlying principles and adapt them to meet human needs. Biomimetic technology has been utilized in various forms from the distant past to the present, and it remains a field that requires ongoing research to discover new principles in nature and put them to use.
