□ DGIST (President Lee Kunwoo) has announced that a research team led by Dr. Lim Sang-kyu in the Department of Energy and Environmental Technology has developed a smart fiber sensor that can detect natural disasters such as landslides in real time. The new fiber is based on piezoelectric technology, which converts pressure into electricity. Its three-dimensional (3D) structure dramatically improves performance, facilitating the implementation of a self-powered sensor system that can operate without an external power source.
□ Piezoelectric fibers generate electricity when pressed or bent. These materials are used in wearable devices, smart fiber sensors, and energy-harvesting devices. However, conventional fiber structures have multiple air layers that have an unknown effect on performance. Hence, the structure limits power output.
□ The research team developed a new nanomaterial, tin titanate nanorods (SnTiO₃NR), which they fabricated into piezoelectric fibers using Polyvinylidene fluoride (PVDF), a polymer. The fiber has an eight-pronged cross-section that resembles flower petals. It is woven, using a special weaving technique, into a 3D double-raschel structure with two overlapping layers. Within the structure, an air layer is formed between the fibers that helps absorb shock, transmit pressure, and amplify signals.
□ According to the research results, the fiber sensor can generate a voltage of up to 92.8 V and a current of 4.13 mA when a pressure of 1 Nm-2 is applied to a 5 cm × 5 cm area––enough to light 22 LEDs without an external power source. That power is also sufficient to run everyday sensor systems or small electronic devices. This demonstrates that a simple change in fiber structure can substantially improve performance. Notably, the power output is more than double that of conventional planar structures, demonstrating the exciting potential of high-performance smart fibers.
□ The research team also used the fiber to implement a Bluetooth-based real-time landslide detection system that can operate without an external power source. The system can detect external forces and transmit data wirelessly. It can therefore be used in various fields in a range of applications from detecting signs of disasters, such as landslides caused by heavy rain, to tracking health and exercise records.
□ Dr. Lim Sang-kyu commented as follows: “We have identified structural and non-structural factors that can enhance the performance of piezoelectric fibers. Our research can contribute to the development of smart sensing technologies, which can be used to preemptively respond to various disasters such as landslides caused by heavy rain.”
□ The research was supported by DGIST’s institution-specific research program. The research was published in the April 21, 2025 online edition of Advanced Functional Materials, an international authoritative journal in the field of materials science.
