Self-powered water sensor uses wave energy to detect pollutants

A new self-powered water sensor uses wave energy to monitor pollutants like heavy metals, microplastics, and pesticides—no battery needed.

Clean water is essential for life—but ensuring it stays clean is a challenge, especially in remote or polluted areas. Researchers have now developed a breakthrough technology: a compact, battery-free water monitoring system that runs on the natural motion of waves.

The innovation integrates two core components. First, a rotational triboelectric nanogenerator (R-TENG) captures energy from water movement, converting it into electricity.

This harvested energy powers a highly sensitive transistor-based sensor made from AlGaN/GaN materials, known for their stability and performance under harsh environmental conditions. The study is published in Nano Energy.

The sensor can detect a variety of harmful substances—including heavy metals (like lead, arsenic, and chromium), pesticides, and even tiny plastic particles—with remarkable precision.

Encased in a waterproof acrylic housing and driven by magnets, the device operates continuously underwater, producing a stable voltage even in high humidity. It charges a small capacitor in about 10 seconds, which then fuels the sensor for real-time measurements.

In lab and river tests, the system demonstrated excellent reliability, distinguishing pollutants down to nanomolar levels and showing a strong linear response to changes in water pH.

Importantly, this self-powered sensor removes the need for batteries or power cables, which often hinder long-term environmental monitoring. By harvesting wave energy, it enables sustainable, long-duration deployment in oceans, rivers, and lakes—supporting both ecological protection and public health.

“This compact, self-powered device offers a smart solution for remote water quality monitoring and early pollution detection,” says Prof. Zong-Hong Lin.