Electric fish inspires murky-water camera
Back in 2016, a scientist from Germany's University of Bonn discovered how the African elephantnose fish can switch between its visual and electrical sensory systems. Now, a team led by that same researcher has developed a camera which mimics the fish's electrical sense of "sight."
Because the elephantnose fish is nocturnal, its eyes aren't of much help when it comes to locating prey and avoiding underwater obstacles.
Instead, the animal generates electrical pulses in an organ located in its tail. Emitted 80 times per second, these signals travel through the adjacent water, and are then picked up by electroreceptor organs in the fish's elephant-trunk-like chin. By analyzing the manner in which the signals are modified by the surrounding environment, the fish is able to perceive shapes, estimate distances, and even differentiate between living and inanimate objects.
Led by Prof. Gerhard von der Emde, a Bonn team has found that there are actually two types of electroreceptors involved in the process – one of these solely measures the signals' intensity, while the other measures their waveform. By analyzing the ratio of the two, the fish is able to identify the mosquito larvae upon which it feeds, among other things.
Based on this finding, the scientists created a prototype short-range camera (pictured above, alongside a plant stem) that utilizes a similar setup to obtain "electric images" of objects in dark environments. The device generates a weak electric field that surrounds itself, while also using an array of electrodes on its surface to measure how the intensity and waveform of the electrical signals are modified by the environment.
In this way, the camera has been able to image natural objects such as fish, plants and wood, along with artificial items including spheres and rods made of plastic and aluminum. Additionally, by analyzing changes in objects' "electrical outlines," the device can tell whether or not an item is moving.
Once the technology has been developed further, it could ultimately find use in applications such as drones or robots that are able to "see" in murky waters, or in the fields of medicine or biological science.
A paper on the research was recently published in the journal Bioinspiration and Biomimetics.
Source: University of Bonn