Researchers from the Institute of Metal Research (IMR) of the Chinese Academy of Sciences have developed an innovative flexible sensor that can simultaneously detect strain, strain rate, and temperature using a single active material layer, representing a significant advance in multimodal sensing technology.

The study, published in Nature Communications, addresses the longstanding challenge of conventional sensors  requiring complex multilayer designs that integrate different materials for distinct sensing functions. These traditional approaches often involve complicated signal acquisition and external power supplies, limiting their reliability in continuous monitoring applications.

Led by Prof. TAI Kaiping, the researchers designed the sensor based on a specially designed network of tilted tellurium nanowires (Te-NWs). Through material and structural engineering, they overcame a fundamental limitation where thermoelectric and piezoelectric signals could not be collected in the same direction within conventional materials. In this unique architecture, both signals are simultaneously detected and output in the out-of-plane direction.

The sensor demonstrates exceptional performance with strain sensitivity of 0.454 V, strain rate sensitivity of 0.0154 V·s, and temperature sensitivity of 225.1 μV·K⁻¹, surpassing the performance of previously reported multimodal sensors.

This work provides new insights for developing flexible, single-channel multimodal sensors based on multi-physics coupling effects. The researchers emphasized that the strain rate sensing capability is particularly important for dynamic scenarios, as the deformation rate significantly influences material response.

Supported by first-principles calculations, the study reveals how charge redistribution in tellurium (Te) atoms generates piezoelectric effects and how external fields such as thermoelectric potentials modulate these signals. This study opens new application possibilities for coupled "nanogenerator" systems in fields including artificial intelligence, biomedical monitoring, and flexible electronics.

Design and microstructural characteristics of the flexible single-channel strain/strain rate-temperature multimodal sensor (Image by IMR)

Application demonstration and verification of the flexible single-channel strain/strain rate-temperature multimodal sensor (Image by IMR)