Recently, Prof. Zhang Jiuyang’s research team from the School of Chemistry and Chemical Engineering, SEU, has published a groundbreaking study, titled Single Polymer Fiber-Based Ultrasensitive and Multifunctional Flexible Microsensor via Arthropod-Inspired Crack-Helix Coupling, in the world-renowned academic journal Proceedings of the National Academy of Sciences of the United States of America (PNAS). Based on polymer surface metallization technology, the team developed a novel polymer–metal hybrid fiber material. Thanks to its helical structural design, the fiber exhibits exceptional resolution of dynamic shear forces and has been applied in biomimetic intelligent electronics.
Polymer–metal hybrid composites hold great promise for precision sensing, wearable devices, and soft robotics. Investigating the deformation mechanisms of such composites under dynamic strain/stress fields is critical for innovating functional paradigms of intelligent electronic devices. To address this challenge, the team innovatively designed an ultrafine polymer fiber with a helical structure and achieved ultra-thin liquid metal surface coating (metal layer thickness: 2.5 μm). The research focused on the deformation mechanisms under dynamic shear (including strain and stress). Inspired by the coupled sensing ability of arthropods in nature, the team applied this novel composite to intelligent electronics and obtained an electronic functional device (crack-helix microsensor, CHMS) with ultra-high sensitivity (GF > 2746). The CHMS is similar in size to a fingerprint ridge and can produce a deformation of approximately 100 μm under an extremely small stress of 0.2 mN. The amplification effect of the CHMS helical topology on external dynamic shear is key to its outstanding resolution (Fig. 1).
Figure 1 Polymer and metal blended materials and their functionalized fiber devices
The team systematically investigated the mechanism underlying the ultrasensitive resolution of the CHMS under tiny dynamic deformations. Under 0–3% strain, the gauge factor (GF) ranges from 271 to 2746, with a detection limit as low as 0.05% strain. Under dynamic tensile shear, the thin liquid metal layer on the fiber surface is affected, generating abundant microcracks, forming a pathway pattern with alternating high and low resistance, which ultimately results in a significant macroscopic resistance change. Microscopic observations reveal that, under cyclic dynamic shear, the highly fluid liquid component (gallium, Ga) can rapidly repair microcracks, significantly improving the electromechanical stability of the CHMS.
Based on the above mechanism and polymer surface metallization technology, the CHMS enables ultrasensitive resolution of weak dynamic shear in various complex environments, including air, underwater, and on the ground. The CHMS can accurately distinguish vibrational shear with different amplitudes (less than 70 μm). Notably, the underwater CHMS can precisely identify high-frequency underwater acoustic waves at different frequencies (256–1088 Hz) with an error of only 0.4–1.1%.
Prof. ZhangJiuyang’s team, with their major focus on polymer–metal hybrid composites,mainly probesinto the fundamental principles and industrial applications of these materials in electronic packaging and electronic functional devices.ChenZixun, a doctoral candidate, is the first author of the paper, while Prof. Zhang Jiuyang is the sole corresponding author,and SEU is the first affiliation. This work was supported by the National Natural Science Foundation of China and the Natural Science Foundation of Jiangsu Province.
Original paper link:https://www.pnas.org/doi/10.1073/pnas.2529908123
Source: School of Chemistry and Chemical Engineering, SEU
Translated by: Melody Zhang
Proofread by: Gao Min
Edited by: Leah Li
