A breathable, sensitive and wearable piezoresistive sensor based on hierarchical micro-porous PU@CNT films for long-term health monitoring. (10th November 2020)

• Record Type: Journal Article
• Authors: He, Yin; Zhao, Liduan; Zhang, Jianglu; Liu, Liyan; Liu, Hao; Liu, Li
• Is Part Of: Composites science and technology. Volume 200(2020)
• Publication Date: 2020-11-10
• Subjects: Hierarchical micro-porous structure -- Conductive polymer composites -- Wearable piezoresistive sensor -- Breathable -- Sensitive; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2020.108419
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: Creating highly sensitive and comfortable flexible sensors remain a key challenge in the development of electronic-skin. A breathable, sensitive and long-term wearable piezoresistive sensor based on hierarchical micro-porous PU@CNT films and a single-sided electrode were prepared by simple and effective methods. Distilled water is used as a non-solvent to induce the separation of films polyurethane (PU) to create the hierarchical porous structures. The micro-computed tomography is used to quantitatively analyze the 3D structure of the porous films with different PU concentration, which is, a small pore volume of less than 50 μm 3 occupy the majority, the porosities are from 64.25% to 40.27%, and the surface areas are of 5.6 × 10 6 to 12.0 × 10 6 μm 2 . Such micro-porous structures performs the air and moisture permeability of the PU@CNT films and the sensors which are more than 8 times that of non-porous film, and effectively improves the sensitivity of the sensors to 51.53 kPa −1 . The hysteresis error of the porous PU@CNT sensor which possesses a higher specific surface area and lower porosity is optimized by 67.8% and it has high stability (>8000 cycles). Finally, the sensors were successfully to detecting article pulse waves, throat and finger movements, and spatially resolved pressure. Graphical abstract: Image 1