Designs inspired by nature are known as biomimetic designs, or biomimicry. Today, we'll:

1. Summarize all 6 steps of the biomimetic design
2. Describe/propose a design project using a biomimetic approach

Biomimetic Design

The core principle of evolution uses optimization of characteristics through natural selection., passing successful traits to lower generations. The progress of time (3.8 billion years to be exact) has allowed living organisms to try and test different designs. The process of evolution requires that:

1. Genes are passed down from parent to offspring (combine from both parents if sexual)
2. Mutations occur when copying DNA (very rare, but still happens)

Each parent passes a complete set of chromosomes, and the two parent's chromosomes are "crossed over" to produce a child with a combination of genes.

Biomimetic design is a variation on traditional engineering that draws inspiration from biological systems that are already optimized for these purposes.

Case Study: Genetic Algorithms

Searching through a huge number of possibilities for optimal solutions is hard. But using genetic algorithms (or GAs) is a method for moving one population of "chromosomes" (strings of bits representing candidate solutions to a problem) to a new population, using selection together with genetics-inspired operators of crossover, mutation, and inversion.

• The selection operator chooses chromosomes in the population that are allowed to reproduce. Fitter chromosomes produce (on average) more digital offspring than less fit ones
• Mutation randomly changes the values of some bits in the chromosome
• Inversion reverses the order of a contiguous section of a chromosome.

Things like AI are made, rather than from a "top-down" approach where we program the structure ourselves, instead is made by programming "rules" and then notice intelligence emerge from these rules.

A nice thing here is that this evolutionary process is very parallel, since millions of these "species" will change all at once within a generation. And yet the rules are developed in such a simple manner.

Steps in the Biomimetic Method

1. Identifying the Specific Function to be Developed: study the particular processes that are unknown and seem to be critical in the biological sense.
2. Gathering the Material: Develop the needed knowledge to understand the biological processes at work in sufficient depth. Have specific questions in mind.
3. Classifying the Material: Find and classify important traits, as well as make sure that those traits are seen in other independent species or tests.
4. Imitating Nature: we don't have to imitate nature per say; rather, we'll first imitate, then test and understand the necessary and unnecessary parts.
5. Technology Assessment: If we don't have specific good technology yet, such as muscle-like actuators, then we should either abandon the imitation, or develop the needed novel technology.
6. Final Design: Determine if new principles have been learned, and if so whether the technology is available to implement them.

An Example

Assume we know little about fluid dynamics and want to construct a fin to control the motion of a fast submarine.

• First, the shape. Should it be thin or thick? Look to whale fins to get the shape of the "streamline" that we intuitively think of.
• ...

Finding the optimal shape of fins was a common problem in the 1950s - 70s, of which this whole thought process became really common. Bird wings conform to what's called this common NACA shape, but the bird ones have paper-thin wings, even though it preferable to use the thicker ones for aircraft. As such, classifying these different types of wings would be good to know when to use one or another.

Case Study: Velcro

de Mestral would go hunting with his dog, and attached to him were cocklebur seeds. He got curious and looked at the structural properties of these seeds to see why they were so sticky.

This search shows the biomimetic design process since:

• (steps 1-3) he identified the biological system that performed a desired function
• (step 4) he found a way to "imitate nature"
• (steps 5) he assessed available technologies to find the best one that performed for his specific purposes
• (steps 6) this final design was so good that it became a standard for so many things!

Biomimicry in the World

See the following for yourself for other examples in the world of biomimicry:

Neural Network Example

Start watching a series on Neural Nets here: