The image above is not a ball bearing on a mirror, but rather a droplet of water on a superhydrophobic surface. A hydrophobic surface is one that water will not ‘wet’, that is a water droplet will not spread out.  Wax is a good example of a hydrophobic surface.  A measure of hydrophobicity is the contact angle between the surface and a drop of water. On a hydrophilic (water loving) substrate the drop will lay very flat and the contact angle will be very small.  As the drop sits higher on relatively more hydrophobic surfaces the contact angle rises.  The maximum contact angle is 180 degrees which would be when the drop nearly floats over the surface it hates touching it so much.  Superhydrophobic surfaces have very high contact angles, for example the lotus leaves I wrote about earlier.  Generally the superhydrophobicity is achieved by starting with a hydrophobic surface and then in some way achieving a nanoscale roughness.  A drop of water sits up on the nanoscale spikes and ridges decreasing the contact area with the surface.  There are several potentially commercially viable methods of achieving the nanoscale roughness, and the determining factor in commercialization seems likely to be the ease of manufacturing the roughness and the durability of the texture.

Biomimetics research falls naturally into four phases. In the first discovery phase scientists try to understand phenomena of a biological system. This research is often little different, or even identical to, the research that basic biologists would engage in. For example, in the run up to Aizinberg’s discovery of the brittlestar’s ability to manufacture microlenses, biologists interested in their biology made observations on light sensitivity. These basic biologists realized that the brittlestar appeared able to ‘see’ a dark area from some distance away, implying a functional eye of some sort. This foundational research is often not seen as ‘biomimetic’ except in hindsight when a clear technology candidate emerges from the biology.

The second phase of biomimetics research, the investigative phase, is when the capabilities and constraints of the biological system are explored. Again using the brittlestar example, the discovery of vision without obvious eyes lured a physical scientist (Aizinberg) into unraveling the phenomenon. She found the microlenses in the arms of the brittlestar and characterized their ability to refract light.

In the third, manipulative phase of biomimetics research the physical understanding of the biological system is tested by manipulating the system to demonstrate controllability and customization possibilities. The brittlestar research has not reached this phase, so take the work of Thomas Fuhrmann on diatoms as an example. The silica cell walls of these algal cells can act as photonic crystals. Furhmann has manipulated the system, adding laser dyes to the growth medium, so that the cell wall can act as micro dye lasers. Since this is still a relatively uncontrolled process and is several steps from commercialization it remains a manipulative phase project.

In the final phase of biomimetics research the biological process has been fully explored and is ready for commercial exploitation. This exploitative phase is such a very long way from the original basic research that often the biomimetic connection seems strained. Nevertheless it is important to realize that the underpinning of the final product was a biological phenomenon. The most often cited example of research that has passed into this highly visible phase is Velcro, the ubiquitous attachment system inspired by the ability of a cocklebur to stick to a dog’s coat.

A form or mechanical function rooted in a design concept found in nature. An example of bioinspired design is the slippery shape of the new Mercedes Benz concept car. Typically products characterized as bioinspired design are close to commercialization or are already commercialized.

An engineering solution derived from a biological solution to a problem. An example of biomimetics is the fog gathering technology envisioned from experiments on materials that mimick a beetle’s back. In general products that are biomimetic have a long period (year to tens of years) between proof of concept and commercialization.

As a practicing comparative biomechanist I find the literature in the related fields of biomimetics, bioinspired design and nanobiotechnology fascinating.  If I were able to turn back the clock and pick a new field of study I would look hard at the interface between nanotech, biology and chemistry.  Since I spend so much time reading journal articles and looking at interesting web sites I decided to leave a trail of breadcrumbs so that you can follow me in my wanderings.

Ilya has been my intellectual foil for as long as I can remember, a voice over the phone, an IM message or a pointed email has pushed me to look harder at a topic or change my thinking on particular results.  Perhaps it is the very different background he has as a chemical engineer turned management guru that always energies my thinking, but in any case, he will be inspiring the entries I make as well as posting his own.

The site will cover a broad swath of the territory that lies between engineering, biology, chemistry and physics. I will not limit the writing and linking to topics directly related to biomimetics, but will make an effort to point out where the research is headed in that world unless the linkage is so distant as to be irrelevant.  In the unlikely event that anyone other than my parents reads this…enjoy.