
2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24

American scientists have created a flexible, stretchable and waterproof device for observing sea creatures. It attaches to the skin and can autonomously monitor the depth, temperature and salinity of water for almost a year. After that, it can be removed from the fish and read the observational data via Bluetooth, the developers report in the npj Flexible Electronics magazine.
Observing the behavior of populations of fish and other marine animals in their natural environment allows scientists to determine the impact of humans on aquatic ecosystems. Often, electronic tags attached to the body of the animal are used for this. But this way of observing has several problems at once. Often, invasive devices are used for observation, which are attached to the fins or other parts of the fish's body. In addition, they can be quite large and heavy in relation to the size of the animal, interfere with its movement, which, in turn, distorts the received data.
A team of engineers led by Muhammad Hussain of the King Abdullah University of Science and Technology has created a device that is more comfortable for marine organisms to track the depth, temperature and salinity of the surrounding water over a long period of time. It is based on an array of polymer-metal elements connected to a readout chip. They have a wavy shape that allows them to stretch with the substrate. Capacitive sensors measure the ambient pressure, and resistance sensors measure temperature and salt concentration in water. The electronic components are attached to an elastic, non-irritating polymer backing. Thereafter, the support can be attached to the test animal.

Device elements
The developers tested the operation of the device on a blue swimming crab (Portunus pelagicus), securing it with cyanoacrylate glue. The authors of the work note that for many other sea creatures, for example, dolphins, it is necessary to use more biocompatible substances. After measurements are taken, the data is read using a Bluetooth device. As noted by the developers, the battery allows the device to carry out continuous measurements with a frequency of taking readings every two seconds for almost a year. In addition, engineers call one of the advantages of the device its low weight - only six grams. The authors demonstrated the process of attaching the device to the ramp:
Recently, American engineers unveiled a robofish for observing other fish in their natural setting. It is equipped with a camera and is wirelessly controlled using acoustic signals. Due to this, the scuba diver-operator can be far from the investigated creatures and not influence their behavior. During tests at sea, the robot swam several times to the fish at a distance of less than a meter, without frightening them.