Yang Jiang, Luo Xingsheng, Liu Shixin, Feng Yirou, Guliakova Anna A, Zhu Guodong
Department of Materials Science, Fudan University, Shanghai 200433, China.
Department of General and Experimental Physics, Herzen University, St. Petersburg 191186, Russia.
ACS Appl Mater Interfaces. 2024 Jul 24;16(29):38334-38344. doi: 10.1021/acsami.4c09892. Epub 2024 Jul 15.
The surge in wearable electronics and Internet of Things technologies necessitates the development of both flexible sensors and a sustainable, efficient, and compact power source. The latter further challenges conventional batteries due to environmental pollution and compatibility issues. Addressing this gap, piezoelectric energy harvesters emerge as one kind of promising alternative to convert mechanical energy from ambient sources to electrical energy to charge those low-energy-consumption electronic devices. Despite slightly lower piezoelectric performance compared with those inorganic materials, piezoelectric polymers, notably poly(vinylidene fluoride--trifluoroethylene) P(VDF-TrFE), offer compelling properties for both flexible mechanical energy harvesting and self-powered strain/stress sensing, though their piezoelectric performance is expected to be further enhanced via varieties of modulation strategies of microstructures. Herein, we reported the controlled epitaxy process of micrometer-thick copolymer films with the cooperation of friction-transferred poly(tetrafluoroethylene) templates and precise modulation of the annealing conditions. Epitaxial P(VDF-TrFE) films present averaged d piezoelectric coefficient of -58.2 pC/N between 50 Hz and 1 kHz with good electromechanical and thermal stability. Owing to the nature of anisotropic crystallization, the epitaxial films exhibit an anisotropic transverse piezoelectric property. Epitaxial films were further utilized for mechanical energy harvesting and monitoring of human pulsation and respiration. This study provided a feasible route for the development of high-performance flexible piezoelectric devices to meet the requirement of flexible electronics.
可穿戴电子设备和物联网技术的蓬勃发展，使得柔性传感器以及可持续、高效且紧凑的电源的开发成为必要。由于环境污染和兼容性问题，后者对传统电池提出了进一步挑战。为了填补这一空白，压电能量采集器作为一种有前景的替代方案应运而生，它能够将环境中的机械能转换为电能，为那些低能耗电子设备充电。尽管与无机材料相比，压电聚合物的压电性能略低，但特别是聚（偏二氟乙烯 - 三氟乙烯）P(VDF-TrFE)，在柔性机械能采集和自供电应变/应力传感方面具有引人注目的特性，不过其压电性能有望通过各种微观结构调制策略得到进一步增强。在此，我们报道了在摩擦转移的聚四氟乙烯模板的协同作用以及退火条件的精确调制下，制备微米厚共聚物薄膜的可控外延过程。外延P(VDF-TrFE)薄膜在50 Hz至1 kHz之间呈现出平均 -58.2 pC/N的压电系数d，具有良好的机电和热稳定性。由于各向异性结晶的特性，外延薄膜表现出各向异性的横向压电性能。外延薄膜进一步被用于机械能采集以及人体脉搏和呼吸的监测。这项研究为开发高性能柔性压电器件以满足柔性电子学的需求提供了一条可行的途径。
