Researchers at Ritsumeikan University in Japan have developed a self-powered biosensor to monitor the pollution of freshwater with organic substances. According to a publication in Biochemical Engineering Journal, the low-cost 3D-printed floating biosensor is based on a microbial fuel cell.
The biosensor uses electrogenic bacteria that generate electricity during their metabolism. The amount of electricity depends on the concentration of organic pollution metabolized by the bacteria. This correlation is used to measure the water quality.
The electrodes of the sensor are made of inexpensive carbon material. According to lead researcher Kozo Taguchi, the bacteria themselves generate the necessary electricity, so no external energy source is required. An LED indicates when a threshold value of the chemical oxygen requirement is exceeded as a measure of pollution.
According to the researchers, the 3D-printed floating biosensor can be used cost-effectively for an early warning system on rivers and lakes to detect pollution peaks caused by organic wastewater at an early stage. It therefore contributes to the protection of aquatic ecosystems.
The scientists see great potential for the practical use of the biosensor to monitor water quality. The low-cost production using 3D printing is an important advantage of the concept.