The Power Of Nature: How IoT Clams Help Keep Polish Water Safe

In a recent video published by Tom Scott, the rumours of clams being used to check the condition of water sources in Poland really is true, and the engineering behind the system is truly ingenious. What challenges does water treatment present, how are clams used as IoT devices, and what does this tell us about the combination of biological entities and internet-enabled technologies?

What challenges does water treatment present?

For as long as civilisations have existed, having access to clean drinking water has been of the utmost importance. Without clean water, diseases can quickly spread, health deteriorates, and living becomes virtually impossible. That is why many past armies would target water sources such as rivers and wells, especially during sieges against castles and fortified areas. In fact, attacking water sources is something that militaries do even today, with one example being the desire for the Ukraine army to reach the Kherson dam so that it can cut off clean water to the whole of Crimea. 

As water is essential for civilisations, humans have invested untold amounts of money and time into developing water distribution systems. The Romans constructed vast aqueducts carrying water for hundreds of miles, ancient Egyptians constructed irrigation ditches, and Victorians established complex water pipe networks powered by massive steam engines. But in recent times, access to modern sciences and technologies allows engineers to distribute vast quantities of water and routinely check its quality while looking for dangerous toxins and pathogens.

However, such testing can be time-consuming and rarely allows for real-time control of water distribution, meaning that a toxin that makes its way into the water supply can reach consumers before tests confirm the presence of said toxins. Worse, the increasing threats faced by terrorism also introduce concerns about mass attacks on a population by tainting the water supply. 

Poland IoT clams provide real-time water testing

Some years ago, there were rumours that Poland engineers use clams to test if their water supply is clean, and many would often disregard these as nothing more than silly stories. However, a recent video posted by the YouTuber Tom Scott has shed light on the rumour and has indeed proven the rumours to be true.

To be clear, engineers in Poland use numerous tests to confirm water quality, but because these tests take time and cannot check for all toxins (each toxin can require different tests), real-time water testing using current techniques is simply not possible. To provide this feature, researchers have instead turned to the faithful clam, which opens and closes depending on the quality of the water it is submerged in.

As clams are filter feeders, they need to be careful not to absorb toxins and pathogens as they cannot remove what they filter (clams make pearls out of the irritants and toxins they absorb). Thus, clams will shut in the presence of unclean water to prevent feeding. But what makes clams interesting is that they can rapidly respond to changes in the water quality, much faster than standard scientific tests for toxin checks, making them a valuable tool for real-time testing. 

But having an engineer physically observe clams in a tank is time-consuming and inefficient, so researchers instead attached a spring and a magnet to numerous clams that each have an associated magnetic sensor. As the clam opens up, the distance between the magnet and sensor reduces, which in turn changes the output of the magnetic sensor. The data from the magnetic sensor is sent to a remote IoT server, which can signal controls to turn off the water if the clam closes its shell.

However, not all clams are alike, and so researchers utilise around 8 clams in a specialised tank, all of which are connected to the server. From there, if some clams shut, it is highly likely that there is an issue with the water quality. Furthermore, to ensure that clams provide a repeatable and reliable output, they are each selected for their size, acclimated to the water supply, and then calibrated for their opening and closing angles. After 3 months of service, the clams are placed back in the natural environment where they were found and then marked so they won’t be used again.  

How the fusion of biology and electronics could power future electronics

Researchers are increasingly turning towards biological-based systems for experimental sensors and computers, and when considering the advantages that biological matter presents, it makes perfect sense. In the case of sensors, researchers are starting to explore the use of field-effect transistors with gates that are sensitive to specific chemical compounds such as antigens and receptors. This allows for a FET to combine with a single molecule and thus observe the reaction in real-time as an electrical signal. 

At the same time, researchers are utilising neuron clusters to execute AI algorithms and control basic robotic systems. Biological neuron clusters provide numerous advantages over traditional electronic systems, including the ability to grow, learn, and use minimal amounts of energy. Thus, future robotic systems may be powered by such clusters, effectively giving machines a brain. 

Nature has spent 4 billion years perfecting life, so it makes perfect sense to take full advantage of this. Instead of trying to create ultrafast electronic sensors to react to real-time changes, attaching a magnet to a clams shell is far cheaper and more effective.