July 27, 2023 | David F. Coppedge

To Solve Problems, Look to Nature

A wealth of engineering solutions is
all around us if we but observe and learn

 

 

King Solomon told the sluggard to “look to the ant… consider her ways, and be wise.” The principle of finding wisdom in nature continues apace today, as scientists watch animals skillfully solving problems that humans need to deal with and get inspired by what they find. Who knows how many more wonderful inventions can come from nature? If imitation is the sincerest form of flattery, scientists are (sometimes unwittingly) honoring the Creator of these creatures by trying to imitate them.

 

Insects

Cicadas could hold the secret to self-cleaning surfaces (The Conversation, 12 July 2023). Sreehari Perumanath at the University of Warwick was inspired by biomimetics to inspire others to take inspiration from nature.

Nature is inspiring scientists all the time. Some ideas are still in research, like beaver-inspired super-warm wetsuits. But others are already part of human life, like velcro (based on burdock burrs) and the Japanese bullet train (modelled on kingfishers’ long narrow beak).

Cicadas inspired my team’s recent research into self-cleaning surfaces.

Perumanath gives the credit for this elegant solution to Darwin:

Cicadas are not the only insects that have evolved self-cleaning bodies. Many butterflies have wings that can clean themselves. Other creatures like geckos and certain plant leaves, such as lotus and rice, also use droplet motion to keep themselves free from dust as cicadas do.

By studying the mechanism used by cicadas to keep their wings spotless, he got an idea. His team observed that water from morning dew beads up on the wings then drops off, carrying dust and bacteria with it. This happens by two mechanisms: a waxy coating that repels water, and microscopic cone-shaped structures that prevent it from penetrating the surface. The beads merge and then jump off like a rising hot air balloon. Think of how skyscraper windows, camera lenses and solar panels could benefit from imitating this trick.

In the future, engineers can incorporate what we learned about cicada wings into product designs, and we may not need to splash water and wipe our windowpanes and other surfaces anymore because they will clean themselves.

Scientists use ORNL’s Summit supercomputer to learn how cicada wings kill bacteria (Oak Ridge National Laboratory, 12 July 2023). Meanwhile, at Oak Ridge lab, scientists trained their supercomputers on cicada wings to see how they don’t just remove bacteria but actually kill them. How? The wing is covered with “nanopillars” that are spaced in such a way that they stretch a bacterium’s membrane to the rupture point. The wing then sheds the carcass of the bacterium through the jumping mechanism described by the University of Warwick team. ORNL engineers reproduced nanopillars that “just naturally kill and clean by themselves.”

A butterfly’s first flight inspires a new way to produce force and electricity (Singapore Institute of Technology and Design via Phys.org, 25 July 2023). What’s inspiring about the way a butterfly unfolds its wings? The material.

During the unfolding, the chitinous material becomes dehydrated while blood pumps through the veins of the butterfly, producing forces that reorganize the molecules of the material to provide the unique strength and stiffness necessary for flight. This natural combination of forces, movement of water, and molecular organization is the inspiration behind Associate Professor Javier G. Fernandez’s research.

A mechanical hand made by the researchers provided grip, leading to possibilities for artificial muscles. Not only that, the material absorbed energy as it dehydrated. Measurements showed that “the mechanical motion of the films in response to humidity changes was converted into electrical currents suitable to power small electronics.”

Reptiles

Bot Inspired by Baby Turtles Can Swim Under the Sand (UC San Diego, 18 July 2023). The clip below, derived from Illustra Media’s documentary Living Waters, delights viewers by showing sea turtle hatchlings emerging from their nest under the sand and making a mad dash for the water.

Moving through sand is difficult for any creature, and creating a robot that could do it is a big challenge. Knowing the baby sea turtle’s ability to “swim” in sand with their flippers, engineers at UC San Diego were inspired to build a robot mimic.

The team believed that observing animals would be key to developing a bot that can swim in sand and dig itself out of sand as well. After considering worms, they landed on sea turtle hatchlings, which have enlarged front fins that allow them to surface after hatching. Turtle-like flippers can generate large propulsive forces; allow the robot to steer; and have the potential to detect obstacles.

Their first sand bots had some success, but “Scientists still do not fully understand how robots with flipper-like appendages move within sand.” Their bot slowed down in wet sand, which has more resistance, but the baby turtle speeds right on through it. The living turtle is better at detecting obstacles and orienting itself.

The engineers at UC have a lot of work to catch up to nature’s sand swimmer. When they do, their invention could help with “inspection of grain silos, measurements for soil contaminants, seafloor digging, extraterrestrial exploration, and search and rescue.”

Mammals

Exterminating greenhouse pests with bat-inspired drones (Society for Experimental Biology via Phys.org, 5 July 2023). Dayo Jansen, a Ph.D. student from student from Wageningen University, tackled the problem of pests in greenhouses. Inspired by bats which capture insects in flight, he wondered if he could train drones to search and destroy, too. Moths invade large greenhouses trying to grow food crops (see also article on this for Pest Management Professional).

Jansen trained his drones on moths after studying their flight patterns. Unfortunately, the moths freaked out at the buzzing of the drones. By aiming ultrasound at them, he got them to freeze in place like a deer in the headlights. The articles don’t say if the drones eat the moths. But with all this work, why doesn’t he build belfries in the greenhouses for live bats? Maybe that method could serve a double purpose: the guano could serve as fertilizer.

California aims to tap beavers, once viewed as a nuisance, to help with water issues and wildfires (Associated Press, 26 July 2023). California has problems with wildfires, loss of biodiversity and depletion of groundwater. Leave it to beavers to help alleviate these crises. Earlier landowners often considered them pests for chewing up trees and shrubs and blocking streams. Not any more:

California recently changed its tune and is embracing the animals that can create lush habitats that lure species back into now-urban areas, enhance groundwater supplies and buffer against the threat of wildfires.

Rather than build robotic beavers, some state officials want to employ live beavers to work as ecosystem engineers for the state. Just let them do what comes naturally.

Supra-orbital whiskers act as wind-sensing antennae in rats (Mugnaini et al., PLoS Biology, 6 July 2023). It’s not clear why scientists from Woods Hole Marine Laboratory took an interest in rat whiskers, but something made them curious about whether the supra-orbital whiskers on their faces (the ones that extend out and up) act as wind sensors. By trimming them and watching the rats’ behavior, the team of 8 scientists found that, lo and behold, the whiskers do provide “anemotaxis” or wind sensing. When trimmed, anesthetized rats did not turn in response to airflow.

The paper does not mention any applications of this knowledge, but pure science is often a precursor to invention. Some engineer might take note of the findings to build airflow sensors inspired by rat whiskers.

Plants

ROSE: A Revolutionary, Nature-Inspired Soft Embracing Robotic Gripper (Japan Advanced Institute of Science and Technology, 12 July 2023). Inspiration for a gripping device that can pick up multiple types of objects came from the way rose petals open and close.

Engineering photosynthesis, nature’s carbon capture machine (PLoS Biology, 14 July 2023). Efforts continue to do what plants and photosynthetic microbes make look so simple: capture sunlight and make food. Although this paper claims that photosynthesis is not an efficient process, it is responsible for most of the life on earth. There are reasons why plants do not extract more sunlight energy than they need: such as to prevent burning and overheating of their photocenters. Plus, they have many other functions to worry about. Have engineers succeeded in improving on photosynthesis? No; they only see it happening in models. The paper is an exercise in hope, not experimental or engineering success. Author Megan Matthews seems more worried about climate change than biomimicry.

Cells

Capturing the immense potential of microscopic DNA for data storage (National University of Singapore, 11 July 2023). Use of DNA for computer storage is in the news again. The “global data overload” may be solved by using DNA instead of microchips, because of the “immense potential” for information in nucleic acids. “As we push the boundaries of DNA data storage, there is an increasing interest in bridging the interface between biological and digital systems,” said one of the researchers.

We often chastise evolutionary biologists for their propensity to make up stories about how things “emerged” through the Stuff Happens Law. We also criticize the leftist bent in Big Science and Big Media. But we love good empirical science, especially when it has potential to improve our lives. More power to the researchers engaged in biomimetics!

 

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