Biomemetics This Time: Tunable Photonic Materials

Another Astonishing Design

We have discussed some amazing examples of how species control their color (here and here, for example) and how such technology in nature has inspired engineers creating advanced new technologies such as low-power video displays. Now new research is helping to explain how squids and octopuses change color and it is amazing.

We usually think of color as resulting from chemistry, such as in dyes. But different colors can also result from repeating, detailed submicron geometrical structures at the object’s surface. The new research reveals yet another, even more complex system for manipulating the frequency of light (i.e., the color) coming from squids and octopuses.

It begins with nerve signals which are sent to special cells containing special proteins. The signal causes the proteins to congregate and deep pleats to form in the cell membrane, altering the osmotic pressure and ultimately its refractive index.

Here is how one of the researchers described the process:

Initially, before the proteins are consolidated, the refractive index -- you can think of it as the density -- inside the lamellae and outside, which is really the outside water environment, is the same. There's no optical difference so there's no reflection. But when the proteins consolidate, this increases the refractive index so the contrast between the inside and outside suddenly increases, causing the stack of lamellae to become reflective, while at the same time they dehydrate and shrink, which causes color changes. The animal can control the extent to which this happens -- it can pick the color -- and it's also reversible. The precision of this tuning by regulating the nanoscale dimensions of the lamellae is amazing.

And here is a more technical description, from the journal paper:

Squids have used their tunable iridescence for camouflage and communication for millions of years; materials scientists have more recently looked to them for inspiration to develop new “biologically inspired” adaptive optics. Iridocyte cells produce iridescence through constructive interference of light with intracellular Bragg reflectors. The cell’s dynamic control over the apparent lattice constant and dielectric contrast of these multilayer stacks yields the corresponding optical control of brightness and color across the visible spectrum. Here, we resolve remaining uncertainties in iridocyte cell structure and determine how this unusual morphology enables the cell’s tunable reflectance. We show that the plasma membrane periodically invaginates deep into the iridocyte to form a potential Bragg reflector consisting of an array of narrow, parallel channels that segregate the resulting high refractive index, cytoplasmic protein-containing lamellae from the low-index channels that are continuous with the extracellular space. In response to control by a neurotransmitter, the iridocytes reversibly imbibe or expel water commensurate with changes in reflection intensity and wavelength. These results allow us to propose a comprehensive mechanism of adaptive iridescence in these cells from stimulation to color production. Applications of these findings may contribute to the development of unique classes of tunable photonic materials.

What we see here is a beautiful design consisting of a sequence of highly complex, intricate and finely-tuned mechanisms, molecules and structures allowing these organisms to precisely control their image. There is no scientific evidence that such optical technology arose from random mutations as evolutionists believe. Evolutionists like to call upon natural selection as a sort of natural designer, but that does not help for such intricate designs as these.

Look at This Incredible Insect Wing Design

A Rational Design

It is intuitively obvious that insect wings, such as these shown from the desert locust, did not evolve from random chance events as evolutionists insist they did, and new research is helping to elucidate the underlying reasons. One glance at the insect wings pictured here reveals something special, but what is it? There is a definite pattern revealed by the crisscrossing veins and the new research demonstrates that the cells formed by the intersecting veins are optimized to minimize the weight of the wing while maximizing the wing’s resistance to cracks. Specifically, the cell’s are sized according to the so-called “critical crack length” which is the length at which a crack becomes a structural threat—a property of the wing material. Cracks shorter than this length tend not to grow and so need not be stopped. So the mechanical properties of the wing material (cuticle), and the structural design of the veins, work together to form an optimized wing. As the research concluded:

the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically ‘optimal’ solution with high toughness and low weight.

The research also found that distribution of the cell size across the wing followed the pattern of smaller cells tending to cluster along the wing edges where cracks might be more likely to begin. As one of the researchers concluded:

Thanks to this precise spacing of the cross veins, the cracks are always stopped before they can reach this critical length and start growing themselves. Nature has found a mechanically “optimal” solution for the locust wings, with a high toughness and a low weight.

It is another example that, as William Bialek has pointed out, biological designs are rational. That is, rather than explaining that the species are the way they are because that is the way they happened to evolve, the species have designs that can be understood according to the underlying engineering and physics principles.

And so using this rational, mathematical, approach to biology the researchers were able to do something that consistently eludes evolutionists—produce a successful prediction:

An optimal cell size of a grid-like structure such as the wing can be predicted using the “critical crack length” of the membrane, which is determined by the material’s fracture toughness and the stress applied. … An “optimal” wing cell should have a diameter of around 1132 µm. Is this the case in locust wings? Our results show that the distribution of the wing cell size in locust wings corresponds very well to this prediction, with the most common wing-cell “class” being between 1000 and 1100 µm.

These wing designs enable the desert locust to achieve tremendous feats of flying, and the designs are yet another example of evolution’s anti-realism. Biological structures certainly appear to be designed but, evolutionists insist, it is a case of false appearances. The designs are that way because that is how they happened to evolve. That, evolutionists say, is a scientific fact that we must not question.

A Marine Mollusk Grinds Down Rock

It May Lead to Better Engineering Machinery

Algae do not merely grow on rocks, they also grow in the cracks and crevices of rocks making the seaweed organisms a difficult meal for consumers such as Cryptochiton stelleri, otherwise known as gumboot chiton, a marine mollusk off the coast of California. This tenacious chiton solves the problem by grinding down rocks with an amazing set of teeth which contain the hardest known biomineral, magnetite. The outer shell of the chiton’s teeth, as professor David Kisailus explains in his latest paper, develop in four distinct stages:

(i) the formation of a crystalline α-chitin organic matrix that forms the structural framework of the non-mineralized teeth, (ii) the templated synthesis of ferrihydrite crystal aggregates along these organic fibers, (iii) subsequent solid state phase transformation from ferrihydrite to magnetite, and (iv) progressive magnetite crystal growth to form continuous parallel rods within the mature teeth.

What is remarkable is that the formation of this advanced,  super-hard material, occurs at standard temperature and pressure. This inspires Kisailus to use these same strategies to produce cost-effective, advanced nanomaterials.

That’s a great idea. An even better one would be to steal the chiton’s designs for using its teeth to grind down rock. As one report explains:

Over time, chitons have evolved to eat algae growing on and within rocks using a specialized rasping organ called a radula, a conveyer belt-like structure in the mouth that contains 70 to 80 parallel rows of teeth. During the feeding process, the first few rows of the teeth are used to grind rock to get to the algae. They become worn, but new teeth are continuously produced and enter the “wear zone” at the same rate as teeth are shed.

The report explains that all this evolved. In other words, random mutations just happened to construct the elaborate process of forming the chiton’s teeth and the complex structures, mechanisms and processes for using the teeth to grind down the rock, to obtain a modest meal of seaweed.

Every mutation, at every point along the way, must have been random. They could not have been induced by the need of the moment. Those are the rules. Otherwise teleology and final causes would be back in play, and that is not allowed in evolutionary theory.

You see evolutionary theory is not driven by empirical science. It is driven by metaphysics. In fact evolutionists have no idea how the amazing gumboot chiton evolved. But they are certain that it did evolve, because they are certain that everything evolved.

Religion drives science, and it matters.

Biomimetics: Learning From Biology

You Won’t Believe These Designs

What happens when engineers look at biology? Unlike evolutionists, they see designs for all kinds of useful applications. “Biomimicry,” explains one article, “is an incredibly productive technique.”

There are the butterflies whose colorful wings arise from fine scales and ridges creating optical interference, a technology used in low-power video displays. And there is the mosquito's proboscis—its needle that we can barely feel because it is highly serrated. Now we have serrated hypodermic needles that are much less painful.

Termites build mounds that have incredible temperature control. They maintain 87 degrees with a system of vents, drawing air from the ground, which the termites open and close as needed. Now architects are using the same principles for better building designs.

The lotus plant is self-cleaning. Water rolls off its waxy leaves due to its tiny bumps which leave no room for droplets to accumulate. Dirt is picked up by the water rather than sticking to the leaf, a design now used in self-cleaning materials including windows and high-voltage power equipment.

Humpback whales have bumps on their flippers which would seem to create more drag but they actually work better, with a third less drag than smooth versions. Now you can see bumps on turbine and fan blades that are 20 percent more efficient.

The list goes on and on. The skin of sea cucumbers, which can rapidly stiffen, inspired a plastic that can switch from a stiff to a pliable state in seconds. The odd shape of the boxfish is surprisingly efficient and inspired a new automobile design. Rodents self-sharpening teeth inspired a new blade design that is self-sharpening. The amazing gecko feet, which provide strong adhesion via the weakest of forces (the van der Waals forces) inspired the Ghecko Tape and Geckskin, which can hold up 700 pound objects.

Biomimicry works not only because nature is chocked full of incredibly effective and efficient designs, but because so many of these designs are clever and non intuitive. We never would have thought of these designs. The sheer creativity evident in biology is far more striking than its incredible high functionality. Meanwhile evolutionists still can’t figure out why their theory keeps failing.

The Marvelous Flight Capabilities of Birds: Why Evolutionists Never Bluff

“Avian flight,” a new study explains, “is one of the remarkable achievements of vertebrate evolution.” Indeed, there is the “complex biotechnical architecture of avian wings,” the “magic structural wing asymmetries” so important for aeroelastic flight control, and the “extremely precise coordination of the complex wing beat motions, together with a perfect flight guidance and control performance.”

Then there are the flight muscles, sense organs and “extremely developed cerebellum” functioning as a guidance and control computer center. These “biological elements communicate with lightning speed like an autopilot as a biotechnical marvel with unimaginable precision.” As the paper concludes, “With their spectacular flight capabilities, birds are really the inimitable flight artists of nature.”

Unimaginable precision. Spectacular flight capabilities. Extremely precise coordination. How did random mutations create such marvels? Natural selection killed off the mutations that didn’t work, but otherwise was powerless to coax the miracle mutations. Evolution requires that the mutations leading to avian flight, and everything else for that matter, knew nothing of the need at hand. They were random with respect to function.

And yet, they created such wonders as avian flight. A remarkable design that our best engineers still cannot figure out. We know that it evolved, however, because evolution is a fact. And evolutionists never bluff.

Here’s How Designs in Biology Are Being Used in Advanced Engineering

This week’s 243rd National Meeting & Exposition of the American Chemical Society in San Diego featured symposiums on biomimetics where scientists “literally take inspiration from Mother Nature, probing and adapting biological systems in plants and animals for use in medicine, industry and other fields.”

Several papers were presented on the wonders of cellulose and one researcher concluded that “We are in the middle of a Golden Age, in which a clearer understanding of the forms and functions of cellulose architectures in biological systems is promoting the evolution of advanced materials.”

Designs from biological systems are leading to advanced materials? Scientists “literally take inspiration from Mother Nature.” It is amazing how random mutations can create such optimized designs for our best scientists and engineers to learn from.