Sensory Cells Give Dragonflies Smart Wings

Biological Strategy

Dragonflies

AskNature Team

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Move in/Through Gases

Living systems must move through gases (which are less dense than liquids and solids) such as those in the earth’s atmosphere. The greatest challenge of moving in gases is that because the living system is heavier than the gas, it must overcome the force of gravity. Moving efficiently in this light medium presents unique challenges and opportunities for living systems. As a result, they have evolved countless solutions to optimize drag and increase lift so that they can stay aloft and take advantage of variable currents. Additionally, they must overcome gravity when moving from a liquid or solid into the air. The fairyfly, the smallest known insect, is a tiny wasp that must move through the air. To the wasp, air feels like a heavy liquid and to move through it, it uses special feathery oars rather than wings.

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Sense Touch and Mechanical Forces in a Living System

Perceiving touch enables living systems to detect other living systems around them and environmental conditions, such as air movement, water currents, and temperature. This ability can help them sense danger as well as opportunity, as when a Venus flytrap’s hairs sense the presence of an insect to eat. Sometimes, a living system senses touch or mechanical forces at a coarse scale; other times, at a sensitive scale that detects very subtle differences. For example, a human elbow is not nearly as sensitive to textures as human fingertips. Fingertips have dermal ridges and many nerve endings that increase sensitivity, enabling them to explore the environment in detailed ways. Elbows don’t need to sense at that level of detail.

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Sense Motion

Perceiving motion is important for a living system to sense where it is in relation to a moving environment, which is critical in locating resources or wayfinding. This applies whether the environment itself is in motion (such as water movement coming from a nearby fish) or the living system is moving within a stationary environment (such as a bird flying through the air). Because motion dampens over distance and the cost of missing those motion signals is high, living systems must be quite sensitive to these signals. For example, fast-flying big brown bats have microscopic, stiff, domed hairs on their wing membranes that act as a sensor array to monitor flight speed and airflow conditions.

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Insects

Class Insecta (“an insect”): Flies, ants, beetles, cockroaches, fleas, dragonflies

Insects are the most abundant arthropods—they make up 90% of the animals in the phylum. They’re found everywhere on earth except the deep ocean, and scientists estimate there are millions of insects not yet described. Most live on land, but many live in freshwater or saltwater marshes for part of their life cycles. Insects have three distinct body sections: a head, which has specialized mouthparts, a thorax, which has jointed legs, and an abdomen. They have well-developed nervous and sensory systems, and are the only invertebrate that can fly, thanks to their lightweight exoskeletons and small size.

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Dragonfly wings are lined with sensors that help the insect navigate using information about airflow and wing strain.

Nothing, neither dragon nor fly, flies quite like a dragonfly. These delicate creatures have a double set of wings that allowing them to dance through the air with incredible agility. What’s even more amazing is that the wings themselves aid in control, thanks to an array of sensors that deliver information about airflow and wing strain.

The Strategy

Each dragonfly wing is lined with an array of sensors that helps the insect navigate using information about airflow and wing strain. The sensors are spread across the whole span of the wing, and they are connected to the nervous system. The axons of the wing sensors are scaled to compensate for transmission latencies.

The information gathered by the sensors is used by the dragonfly to navigate its environment. The sensors help the dragonfly to avoid obstacles, to find prey, and to mate.

The Potential

The dragonfly’s ability to use information gathered by a network of sensors to navigate its environment could be used to improve our ability to do the same. The sensor array could be used to monitor the structural and aerodynamic state of an aircraft or to control a ground vehicle. The sensor array could also be used to detect motion beyond the range of vision.

It also points to the enormous opportunity for a new generation of sensors in every sector. Infrastructure, textiles, and agriculture could all benefit from the application of biological or biologically-inspired sensors. The dragonfly shows how it could be done.

Last Updated December 20, 2022

References

“Here, we present the first systematic characterization of mechanosensors on the dragonfly’s wings: morphology, distribution, and wiring. By combining a cross-species survey of sensor distribution with quantitative neuroanatomy and a high-fidelity finite element analysis, we show that the mechanosensors are well placed to perceive features of the wing dynamics relevant to flight.”

Journal article

Systematic characterization of wing mechanosensors that monitor airflow and wing deformations

iScience | March 23, 2022 | Joseph Fabian, Igor Siwanowicz, Myriam Uhrhan, Masateru Maeda, Richard J. Bomphrey, Huai-Ti Lin

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Reference

Other Biological Strategies

a macro view of dragon fly wings against a blurry green background

Biological Strategy

Microstructure Offers Efficient Flight

Common skimmer

Wings of dragonflies offer highly efficient flight and lightweight characteristics due to a series of adaptive materials that form a very complex composite structure.