Reviewed by Lauren HardakerJul 7 2025
A pioneering new gadget created by a team of researchers led by Associate Professor Benjamin Tee from the National University of Singapore’s Department of Materials Science and Engineering, College of Design and Engineering, has the potential to greatly improve water quality monitoring and management. The study was published in the scientific journal Nature Communications.
Associate Professor Benjamin Tee (right), Dr Liu Mengmeng (left), Dr Yu Kelu (center) and their team from the National University of Singapore have developed the ReSURF sensor – an ultrafast, stretchable, self-healing and recyclable sensor for real-time water quality monitoring – and tested it on a pufferfish-like soft robot. Image Credit: College of Design and Engineering at NUS
Clean, safe water is essential to human health and well-being. It also contributes significantly to food security, aids high-tech enterprises, and promotes sustainable urbanization. However, detecting contamination promptly and properly is still a big difficulty in many regions of the world.
Inspired by the biological function of the oily protective layer present on human skin, this notion was turned into a multifunctional material known as ReSURF, which could spontaneously generate a water-repellent interface.
This novel material, which can be created using a quick micro-phase separation technique, self-heals and can be recycled. The material was put into a device known as a triboelectric nanogenerator (TENG), which generates an electric charge by converting the energy of moving water droplets. The resulting gadget, the ReSURF sensor, could be used to check water quality.
The ReSURF sensor can detect various pollutants, such as oils and fluorinated compounds, which are challenging for many existing sensors. This capability, together with unique features such as self-powered, self-healing, reusability and recyclability, positions ReSURF as a sustainable solution for real-time, on-site, and sustainable water quality monitoring.
Benjamin Tee, Study Lead and Associate Professor, Department of Materials Science and Engineering, National University of Singapore
Rapid and Sustainable Water Quality Sensing
Existing water quality monitoring methods, such as electrochemical sensors, optical detection systems, and biosensors, are efficient for detecting heavy metals, phosphorus, and microbial pollutants.
However, these technologies frequently have disadvantages such as sluggish reaction times, high prices, dependency on external reagents or power sources, limited reusability, and the requirement for cumbersome laboratory equipment or specialized instrumentation.
The NUS team created the ReSURF sensor, which efficiently solves these problems, notably in on-site real-time water quality measurement. The self-powered gadget can identify water impurities in around 6 milliseconds (about 40 times quicker than a blink of the eye).
Additionally, the ReSURF sensor is self-healing and recyclable, making it a low-maintenance and environmentally friendly option. The material's stretchability and transparency allow it to be readily incorporated into flexible platforms such as soft robotics and wearable electronics, distinguishing it from traditional sensing materials.
Furthermore, the ReSURF material employed as a sensor provides an environmentally beneficial alternative because it is easily recyclable due to its solubility in solvents, allowing it to be reused in new devices without losing functionality.
ReSURF Sensor: How it Works
The ReSURF sensor measures water quality by analyzing the electrical signals produced when analytes (such as salts, oils, or contaminants) in water droplets come into contact with its surface. When water droplets containing analytes touch the sensor's water-repellent surface, they spread out and glide away swiftly, generating electric charges in milliseconds.
The magnitude and nature of the signal created would differ depending on the composition and concentration of the analytes present. By monitoring these signals in real time, the ReSURF sensor can check water quality quickly and precisely without the need for additional power sources.
To illustrate its capabilities, the researchers tested the ReSURF sensor on a pufferfish-like soft robot for oil in water and perfluorooctanoic acid, a common contaminant found in water sources. The test yielded promising findings, with both contaminants creating distinct voltage signals, demonstrating that the ReSURF sensor can be employed in the early detection of potential contamination.
Safeguarding Water Quality
The ReSURF sensor has numerous application possibilities. It can be installed in rivers, lakes, and reservoirs to provide early detection of contaminants and rapid reaction to water contamination emergencies. In agriculture, it may check water quality in places such as rice fields. In industrial settings and sewage treatment plants, the ReSURF sensor could provide useful wastewater management data.
Next Steps
The study team intends to improve the ReSURF sensor’s precision in pollution identification, integrate wireless data transmission capabilities, and scale the system for long-term or large-scale environmental monitoring. Furthermore, the researchers intend to investigate new eco-friendly material options to improve sustainability and comply with changing environmental standards.
Tee added, “Future iterations could integrate additional sensing modalities or machine learning–based signal analysis to enable more precise identification and classification of pollutants. We envision this platform as a foundation for the development of more intelligent and responsive water quality monitoring systems.”
Journal Reference:
Liu, M., et al. (2025) Recyclable self-secreting autonomous healing dielectrics for millisecond water quality sensing. Nature Communications. doi.org/10.1038/s41467-025-59973-y.