New Engineering Ideas from Biology

Photo: A click beetle, by Sarefo, CC BY-SA 4.0 , via Wikimedia Commons.

The 2023 Conference on Engineering in Living Systems, organized by the CSC’s Engineering Research Group, is set for June 1-3 in Denton, Texas. (More info and an application are here.) New engineering ideas from biology? That’s right. Engineers won’t run out of inspiration any time soon if they look at the living world. From cell to ecosystem, life knows how to solve problems — how to engineer solutions, it’s not unfair to say. Here are some new illustrations.

Click Like a Beetle

Robot designers face a show-stopper when their invention falls over. Solution? Design like a click beetle. When this insect gets turned upside down, it launches itself with a rapid click, using elastic energy stored in its exoskeleton. Biologists at the University of Illinois were intrigued. News from the U of I says, with pun intended, “Researchers have made a significant leap forward in developing insect-sized jumping robots capable of performing tasks in the small spaces often found in mechanical, agricultural and search-and-rescue settings.”

Researchers at the University of Illinois Urbana-Champaign and Princeton University have studied click beetle anatomy, mechanics and evolution over the past decade. A 2020 study found that snap buckling — the rapid release of elastic energy — of a coiled muscle within a click beetle’s thorax is triggered to allow them to propel themselves in the air many times their body length, as a means of righting themselves if flipped onto their backs. [Emphasis added.]

A 12-second demonstration of their invention is shown in the article. “This process, called a dynamic buckling cascade, is simple compared to the anatomy of a click beetle,” admitted Samek Tawfick, a mechanical science and engineering professor at the University of Illinois. Obviously, their gadget can’t make babies. 

Control Heat Like a Camel

Firefighters depend on their special suits for protection from the flames but leave the lifesaving heroes soaked in sweat. New Scientist reports, “Fabric inspired by camel’s hump could protect firefighters from heat.” How is that? Camels have had to face heat challenges ever since the first ancient peoples learned to ride them across the desert on trade routes. They were pre-designed for prolonged exposure to the sun’s fiery rays.

Jian Fang at Soochow University in China and his colleagues have developed an insulating fabric that uses pockets of aerogel, in which the liquid component of a gel is replaced with gas. It is sandwiched between two layers of heat resistant plastic polymer. This is said to mimic the fat stores in a camel’s hump.

Camel hair wicks water from the animal’s sweat glands to the outside air. Material that mimics the fat and hair in camels can not only exceed the specifications of today’s firefighting uniforms, but also keep the first responders more comfortable as they work.

The aerogel pockets are produced using ultrasonic welding, where sound is used to melt the two layers of plastic together at various points. This process also creates micropores in the fabric that can wick away moisture. “We created many pore structures, like the camel’s sweat glands, that can guide liquid from inside to outside, helping you when you get sweaty,” says Fang.

When the researchers exposed the fabric to temperatures of about 80°C (176°F) for about 20 minutes, they found that a thermostatic plate covered by it stayed around 20°C cooler than one covered by conventional firefighter uniform fabric. And when it was exposed to a 1000°C flame for 10 seconds, the camel-hump fabric also suffered far less burning and damage.

The engineered “biomimicking” fabric also traps 13 percent less moisture, is cheap, and easy to make. It looks promising.

Echo Like a Bat

How bats navigate through foliage after their target prey presents a difficult challenge. “Foliage echoes in some cases can help bats gather information about the environment,” says a new paper in PLOS ONE, “whereas in others may generate clutter that can mask prey echoes during foraging.” Hongxiao Zhu from the University of Virginia and colleagues from the UK and Japan had already built a “foliage echo simulator” they could use with a “biomimetic sonar head” to investigate how the bat sorts the useful echoes from the clutter. 

In this work, we improve the existing simulator by allowing more flexible experimental setups and enabling a closer match with the experiments. Specifically, we add additional features into the simulator including separate directivity patterns for emitter and receiver, the ability to place emitter and receiver at distinct locations, and multiple options to orient the foliage to mimic natural conditions like strong wind. To study how accurately the simulator can replicate the real echo-generating process, we compare simulated echoes with experimental echoes measured by ensonifying a single leaf across four different species of trees. We further extend the prior work on estimating foliage parameters to estimating a map of the environment.

Bats can make mental maps of their surroundings with sound; that’s remarkable. The research team’s approach — which is engineering all the way down — reveals the complexity of the problem that the bat solves so well: discriminating information from noise in a field of clutter. No mention of evolution was found in the paper. The authors begin their publication with this amazing factoid:

Many bat species rely on echolocation — they emit short ultrasonic pulses and listen for the returning echoes to support navigation and prey hunting. The dominant frequency in bat biosonar pulses can reach up to 212 kHz with thresholds for object detection as low as 0.05 mm — smaller than the thickness of human hair. The extremely capable sonar sensing system coupled with low energy requirements makes bats an excellent biological model for the study of smart sonar systems.

Heal Like a Fungus

Materials scientists have long been biomimetics fans, imitating spider web silk, nacre in oysters, and superhydrophobic leaves of water lilies. In a paper in Nature Materials, researchers from the Netherlands and Switzerland began their paper with praise for the qualities of living materials, particularly fungi. Why mimic them when you can partner with them?

Biological living materials, such as animal bones and plant stems, are able to self-heal, regenerate, adapt and make decisions under environmental pressures. Despite recent successful efforts to imbue synthetic materials with some of these remarkable functionalities, many emerging properties of complex adaptive systems found in biology remain unexplored in engineered living materials. Here, we describe a three-dimensional printing approach that harnesses the emerging properties of fungal mycelia to create living complex materials that self-repair, regenerate and adapt to the environment while fulfilling an engineering function.

This is the 21st-century version of putting a harness on an ox or horse. It took a long time to build an “iron horse” (locomotive) that could exceed the power of an animal. Even so, the engineered copy lacked some of the advantages of the biological inspiration, such as ability to eat grass, make copies of itself and not pollute. If these researchers can harness fungi for clean, self-healing, adaptive “green” technologies, that’s a solution engineers will aspire to.

Smell Like a Dog

A headline from CORDIS asks, “Why can’t we replace sniffer dogs with electronic noses?” Olfaction seems simple in concept; absorb volatile organic compounds (VOC), classify them and identify them according to a lookup table or memory. The reality is much more complicated. Accompanying a photo of a smart-looking German shepherd with nose to the wind, this article gives a status report on progress with “e-nose” technology. The “future is bright” the technology, but after 40 years of work, dogs are still ahead by a nose. Why?

“While it should be possible to train e-noses to smell most things that dogs can smell, dogs retain certain advantages. Their sense of smell is extremely sensitive and can identify VOCs at very low concentrations. Sensors also have shorter lifespans than dogs and are more vulnerable to humidity and temperature,” remarks Roque [a biomechanical engineer in Portugal].

Nose engineers find it difficult to miniaturize the sensors and computers into an autonomous robot, “given the processing power required and the large number of validation samples that the sensors have to accommodate.” So far, e-noses only work for specific types of odorants. Engineers have a long way to go to match the broad talent in dogs that can sniff out everything from squirrels to drugs to cancer cells. Dogs can also detect minute traces of VOCs and chase them along a gradient. Human engineers may need another 40 years.

Evolution Is Like Engineering?

The click-beetle scientist, Sameh Tawfik, repeated a worn-out evolutionary canard that claims evolution is like engineering. He said, “this study plants a seed in the evolution of this technology — a process similar to biologic evolution.” Darwin notoriously compared blind natural selection to goal-oriented artificial selection. In doing so, he created an industry in academia that commits this logical fallacy routinely. Once the magical thinking gets extricated from press offices as the parasitic meme it is, bio-inspired engineering can leap forward with credit going where it belongs — to intelligent design.

The engineering perspective in biology, as exemplified magnificently in Your Designed Body by Steve Laufmann (one of the leaders behind CELS) and Howard Glicksman, offers twin advantages over Darwinism. The first and immediate benefit is practical: ushering in a golden age of new technologies that can bring convenience, safety, and health to everyone. The second — even more significant — is philosophical. It can replace the storytelling of Darwinism that denigrates biology as a heap of junk arrived at by multitudes of accidents, and instead exalt biology with the awe it deserves for solving environmental problems with elegant solutions. This could generate superior understanding of life processes (as engineers attempt to mimic them), imbue life sciences with purpose, and make biology class exciting again.