Appearance of CFRP/KNN-epoxy. Credit: Zhenjin Wang et al

A new multifunctional composite made of carbon fiber-reinforced polymers (CFRP) and piezoelectric materials can use vibrations to self-detect tiny cracks. This material could be used in the aerospace, automotive, and construction industries to monitor structural health without the need for an external power source. The technology was shared in a paper published in the International Journal of Smart and Nano Materials on January 9, 2026.

Why a smarter CFRP is needed

"CFRP is very strong and light. It’s used in airplanes, wind turbines, and other large structures. However, it can fail suddenly when cracks grow inside. Finding these cracks early is difficult and many structures cannot easily use batteries or wired sensors. A self-powered sensing solution is strongly needed," said assistant professor Zhenjin Wang of Tohoku University.

To make CFRP smarter, the researchers integrated a piezoelectric nanocomposite that converts mechanical energy into electrical energy. The piezoelectric nanocomposite is made of piezoelectric nanoparticles and epoxy, which helps balance electrical performance and mechanical strength. For practical use in aircraft and energy systems, the team used a lead-free piezoelectric material, potassium sodium niobate (KNN), instead of conventional lead-based ceramics. This supports safer and more environmentally friendly sensing technologies.

"Our material turns vibration into information. Crack growth can be reflected in the timing of the wireless signals, which enables fully autonomous structural monitoring to support safer aircraft and energy systems," said Wang.

Charging and discharging circuit conditions for lighting LEDs. Credit: Zhenjin Wang et al

How the composite senses damage

Researchers tested both the mechanical strength of the composite and its ability to generate electricity. Under vibration, the material produced an open-circuit voltage of up to 13.6 V. More importantly, when artificial cracks were introduced between the CFRP and the piezoelectric nanocomposite layers, the output voltage and resonant frequency decreased as the cracks became longer. This means the material does not only harvest energy, but it can also "sense" internal damage through changes in its electrical response.

Based on this behavior, the team proposes a new approach that combines energy harvesting, sensing, and structural health monitoring in a single material system. With the piezoelectric "brain," the CFRP can harvest electricity from vibration and use it to monitor key conditions such as acceleration and pressure, while sending the data wirelessly to a computer without any external power supply. In addition, internal damage such as delamination can be detected by analyzing changes in the timing of the received wireless signals.

"Today, inspections need sensors, wires, and power supplies. This new material works by itself. It reduces cost, weight, and maintenance, and improves safety in places where power is limited," said Wang. "In addition to supporting safer aircraft and energy systems, our research will help future smart materials research and advance battery-free sensor technology."

• A schematic diagram of the circuit that drives the wireless integrated device. Credit: Zhenjin Wang et al
• (Left) The transmission interval of the IoT wireless device’s radio waves. (Right) Relationship between crack length and radio wave transmission interval. Credit: Zhenjin Wang et al

Looking ahead, researchers are thinking about the different ways this multifunctional composite could be used for next-generation self-powered structural health monitoring systems. Additional testing will be needed to confirm the durability and stability of the composite to determine its practical uses.

More information

Yuki Sueda et al, From vibration to information: self-powered crack detection and wireless communication in carbon fiber reinforced piezoelectric nanocomposites, International Journal of Smart and Nano Materials (2026). DOI: 10.1080/19475411.2025.2610182

Citation: Self-powered composite material detects its own cracks (2026, January 29) retrieved 29 January 2026 from https://phys.org/news/2026-01-powered-composite-material.html

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