According to Wikipedia.org which though is not often desirable, the meaning of the word biomimetics does not include the direct utilization of the functional part of living structures. We have found lotus leaves superhydrophobic. But biomimetically we didn’t directly grow lotus crops for water-repelling coatings, nor did we try to culture similar layer from lotus tissue. Rather, we got ‘inspired’ and started ‘mimicking’ the structure by purely artificial technologies we are familiar with. Similar situation is in computer science—obviously we didn’t try to clone some people exclusively for intellectual production, leaving us a comfortable yet improving future without necessity to think over anything complex. Rather, we turn to silicon-based computers and only wish these computers can become smarter by mimicking the logical structure of brain—what the cyberneticists are doing. There seems to be a far future perspective of biomimetics where we will have learned how all the living things work in the planet. At that time we will be alright living without any other living things because they are no longer mysterious or fascinating. Or in other words, at that time we will never fear of the extinction of living things because they are no longer Nature’s monopoly; we can create all living things from bottom up.

However, today’s reality does not seem to allow such an biomimetic optimism. Although some structural tricks have been played by scientists, we are still generally helpless in front of the core mechanism of life. Currently we have learned very little from Nature as we estimate, and our biomimetic products are essentially nonliving. While the genius of Natural gifts are extincting at a much faster way than human can catch up, we now still need to rely on living things in many crucial aspects of life besides foods.

Energy source of the matrix in the movie Matrix. From Jason Kurtz’s website.

Whereas biomimetics wishes us to rely less on ecology, with little real success, another idea wishes us to rely more, by exploring the nature and finding new living species that may potentially work for human. The logic is somewhat similar to ‘to grow crops of lotus for water-repelling coating’, but practically this kind of research focus primarily on biofuels, agricultural technology (e.g. mix planting), etc. Although this kind of idea can still be ethically scary if pushed to some extreme (remember the energy producing units in the movie Matrix), it still sounds better than a biomimetic claim that we will kill all fauna and flora when we have known them all (at least in Matrix we still have human).

Shewanella. From http://www.ornl.gov.

And sometimes this kind of research is also seen in materials science. A group of Japanese scientists recently published a paper¹ on Angew. Chem. Int. Ed. describing a electrically conductive bacterial network under some artificial manipulation—a man-made material that functions only when it’s living. The featured bacterium is called Shewanella, which is known capable to recognize and transfer electrons to Fe(III) oxide surfaces². The researchers found that, although individual cells are electrically
insulated from the others, addition of semiconducting Fe₂O₃ colloidal particles to the bacterial culture resulted in a continuous film that is found electrically conductive, provided the food for the bacteria, lactate, is sufficient. It is proved that the conductivity of the film is the result of bacteria, not the added Fe₂O₃ colloids, because pure this colloids were found electrically isolate. The authors said in the paper that this finding is relevant to “designing and fabricating bioanode materials for microbial fuel cells”.

This paper reminded me another earlier one³ published on Adv. Mater., where cells were added to a solution of polymer which is modified with cell recepters, resulting a bio-crosslinked hydrogel. The sol-to-gel transition was characterized by rheological method implying some mechanical properties of the so-formed hydrogel. This cell-croslinking hydrogel was further found reversible—it flows when sheared, and gels again when allowed to stand for a while. This property is important for injectable gel drugs that allow the drug can pass through the syringe while can stay at one place after injection, curing specifically the lesion site. What if we can inject some living cell amendment instead?! And, considering also the former electrical bacteria, what if we can inject some living electronic devices into our bodies where they keep functioning so long as our bodies provide them nutrients for living?

That may be a totally different scene from what biomimetics provides.

¹ Ryuhei Nakamura, Fumiyoshi Kai, Akihiro Okamoto, Greg J. Newton, Kazuhito Hashimoto (2009). Self-Constructed Electrically Conductive Bacterial Networks Angewandte Chemie International Edition, 48 (3), 508-511 DOI: 10.1002/anie.200804750

² Gemma Reguera, Kevin D. McCarthy, Teena Mehta, Julie S. Nicoll, Mark T. Tuominen, Derek R. Lovley (2005). Extracellular electron transfer via microbial nanowires Nature, 435 (7045), 1098-1101 DOI: 10.1038/nature03661

³ K.Y. Lee, H.J. Kong, R.G. Larson, D.J. Mooney (2003). Hydrogel Formation via Cell Crosslinking Advanced Materials, 15 (21), 1828-1832 DOI: 10.1002/adma.200305406