Clean, safe water is vital for human health and well-being. It also plays a critical role in our food security, supports high-tech industries, and enables sustainable urbanisation. However, detecting contamination quickly and accurately remains a major challenge in many parts of the world. A groundbreaking new device developed by researchers at the National University of Singapore (NUS) has the potential to significantly advance water quality monitoring and management.
Taking inspiration from the biological function of the oily protective layer found on human skin, a team of researchers led by Associate Professor Benjamin Tee from the Department of Materials Science and Engineering in the College of Design and Engineering at NUS translated this concept into a versatile material, named ReSURF, capable of spontaneously forming a water-repellent interface. This new material, which can be prepared through a rapid micro-phase separation approach, autonomously self-heals and can be recycled. The researchers incorporated the material into a device known as a triboelectric nanogenerator (TENG), which uses the energy from the movement of water droplets to create an electric charge. The resulting device (ReSURF sensor) can be applied as a water quality monitor.
"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," said Assoc Prof Tee.
The team's design of the ReSURF material and performance of the novel water quality sensor were published in the scientific journal Nature Communications on 1 July 2025.
Rapid and sustainable water quality sensing
Existing water quality monitoring technologies such as electrochemical sensors, optical detection systems, and biosensors are effective in certain specific applications, such as detecting heavy metals, phosphorus, and microbial pollution.
However, these technologies often face limitations including slow response, high costs, reliance on external reagents or power sources, limited reusability, and the need for bulky laboratory equipment or specialised instrumentation.
The ReSURF sensor developed by the NUS team effectively overcomes these challenges, particularly in on-site real-time water quality sensing. The self-powered device has demonstrated the ability to detect water contaminants in approximately 6 milliseconds (i.e. around 40 times faster than a blink of the eye).
Additionally, the ReSURF sensor is designed to be self-healing and recyclable, making it a sustainable and low-maintenance solution. Being stretchable and transparent, the material can be easily integrated into flexible platforms, including soft robotics and wearable electronics, setting it apart from conventional sensing materials.
Furthermore, the ReSURF material applied as a sensor offers an environmentally friendly solution as it can be easily recycled due to its solubility in solvents, enabling it to be reused in new devices without suffering a loss in performance.
ReSURF sensor: How it works
