Biomimetic sensors : Top 5 of the most interesting detectors

The multiple senses of life inspire sensors for detection tools and interactive technologies. Here is the “Top 5 bio-inspired sensors” developed by Bioxegy experts!

Sensor and biomimicry: technology that makes sense! The detection is an essential tool for living beings to know and interact with their environment. If the human being has nine senses (and not five!) to do this, the living has developed and adapted many others. These senses now inspire sensors that support the development of detection tools and interactive technologies.

Sensor 1: an explosives sensor inspired by the Mulberry Bombyx

The mulberry moth, whose antennae inspired this sensor.

Bombix mori, the domestic silk moth (the adult silkworm) has an overpowering sense of smell: the male is able to detect his sexual partners from 16 km away! This capacity is essential to its survival: the moth only lives 15 days in the form of a butterfly, and reproduction is then its only activity (it does not even feed!). Its performance is explained by the operation of its antennas. They are covered with eyelashes with a porous structure to present a maximum surface to the pheromones which come to adhere to them.

Researchers from the University of Strasbourg, the CNRS and the Institut Saint-Louis have developed a sensor inspired by the antennae of the Bombyx to detect TNT. The interest of this sensor? His performance. According to the first tests carried out in the laboratory, the device would be able to detect concentrations up to 0.8 ppt (part by trillion = 10¹⁸), a billion times more accurate than other existing sensors. He also outperforms trained dogs! Researchers are currently working on the transposition of this bio-inspired sensor to allow the detection of all types of molecules, in particular explosives and toxic chemical agents.

Sensor 2: a forest fire sensor inspired by pyrophilic insects

The pyrophilic beetle that inspired this sensor

The Amazon, Australia, California: the flames have spared no area of the globe in recent years. If the flora is mostly destroyed, the fauna is not affected as much! And for good reason: some animals are able to detect forest fires. It is even a vital ability for some insects.

The beetle Melanophila acuminata, also called fire bug, lays its eggs only on burnt trunks. It has a specialized organ to locate its egg-laying sites, making it able to detect a burnt tree at 1 km and a forest fire at 100 km!

Some German researchers were inspired by its infrared detectors to design an ultra-efficient forest fire sensor that reproduces the mechanisms of living organisms! They studied the infrared detection organs of several pyrophilic insects to understand how they work. Their understanding allowed them to design a new biomimetic sensor. This sensor is 80 times more powerful than others on the market. Enough to spot fires much earlier to better protect forests. That's how nature is well done!

Sensor 3: an earthquake sensor inspired by the elephant

Elephants, real sensors of seismic waves

As with forest fires, wildlife is generally spared the ravages of earthquakes and tsunamis. Here again, they are able to sense danger coming in time to get to safety. And once again, these kinds of abilities would serve us well!

Elephants are very good at this: their mass offers them a reserved channel of communication: that of seismic waves. They can thus communicate over very long distances.

An elephant's trunk, fitted with sensors.

Researchers from the The University of Bristol and Oxford studied these vibrations to prove that it was possible to determine the behavior of these giants (walking, running, and even gurgling!) according to the waves emitted, evidence of the potential richness of these exchanges. To decode these messages, elephants have several tools at their disposal: a fatty cushion in their legs which allows them to feel these vibrations, bones which are excellent conductors of vibration, a trunk equipped with Pacini corpuscles (sensor of very fine movement) and ears which are specialized in low frequencies.

NASA is currently developing a fly-eye-inspired sensor to detect seismic vibrations, and these searches provide an interesting new alternative. If we still need to improve our understanding of these mechanisms to develop a new bio-inspired sensor, this research is also useful to us in the development of technologies that absorb or amplify vibrations.

Sensor 4: a sugar sensor inspired by a white butterfly

White-and-black-winged white-winged white turnip

Do you know the cabbage butterfly or small white, scientifically known as Pieris rapae. It bears this name in honor of the Pierides, muses of Greek mythology and the kohlrabi, on which the butterfly likes to lay its eggs. This time, it is not one of the senses of this animal that interests us but the white color of its wings! Like its cousin the Morpho butterfly, with iridescent blue, this color is not due to pigments as in most living beings, but to the structure of its wings. The basic structure of the wing consists of a layer of black pigments surmounted by a grid. It is this configuration that makes the black spots on its wings. On the rest of the wing, the whiteness is created by nanoscale balls (10⁻⁹m) hung on the grid. They make the white color appear by reflecting the incident light.

How does this structure create a sensor? When molecules land on the beads, the trajectory of the light waves is deflected and the color changes. Researchers from the EPFL in Switzerland, have reproduced the structure of the wings with polymers. When wet, their wing turns black. How to make it a sensor! But, their transposition does not stop there! In truth, the perceived color will depend on the refractive index of the medium where the structure is located. The refractive index of a sugar solution varies according to the sugar concentration, it can be determined according to the color of the sensor!

Interest? In the food industry, it is necessary to measure the sucrose content of certain products, like wine. This biomimetic sensor offers a “low-tech” alternative to the refractometers usually used.

Sensor 5: an obstacle sensor inspired by the bat

The bat is well known for its ability to locate itself in space at night. Its hunting strategy, involving the use of ultrasound, allows it to locate its prey and assess its movement in complete darkness.

For humans, sight is the most used sense: our eyes are therefore our primary sensor. Unfortunately, not all our fellow citizens have the chance to observe their environment. Never mind: in the absence of an eagle's view, they can use that of the bat! This is indeed the challenge that the company Ultracane has set itself: a cane for the visually impaired with ultrasonic sensor. Thanks to this sensor, they can detect obstacles on the ground up to 4 meters (depending on the established setting). Second significant advantage of this sensor: detect obstacles in height up to 1.5m away.

Ultra cane

Principle of bat echolocation

So here is a small overview of the best existing biomimetic sensors. But, there are many more! These sensors are particularly useful in the field of robotics: they make it possible to create detection robots. By combining the capacities of living things, it is possible to develop robots with various properties, such as this leak detection robot whose movement is inspired by the jellyfish, the body of the octopus, and the sensor of the blind tetra!