聚丙烯腈自发电水凝胶用于柔性传感

Polyacrylonitrile-based self-powered hydrogel for flexible sensing

水凝胶传感器已成功在生物学和电子产品之间实现了无缝结合,但这些材料通常具有机械性能差、需要外部电源或电池等问题.本文以聚乙烯醇(PVA)、丙烯腈(AN)、对苯乙烯磺酸钠(NaSS)、丙烯酰胺(AAm)为原料, N,N′-亚甲基双丙烯酰胺(MBA)为交联剂制备了一种基于聚丙烯腈的自发电水凝胶(PVA-PAN).通过红外光谱、力学性能测试、力电响应性能测试对其进行性能表征,研究结果表明PAN链间的偶极相互作用和PVA与PAN链段间的氢键作用促进PAN向平面之字形构象转移,水凝胶的最大压电系数d_(33)为32 p/CN,具有与皮肤相类似的杨氏模量值(0.08~5.49 MPa)和良好的延展性(97%~408%).由于应力诱导的极化效应,该自发电水凝胶能够产生约60 mV的电信号输出.通过V-T曲线表明该水凝胶可以通过电压信号的变化精确地检测人体的各种活动(如关节的运动、步频等).本研究制备的自发电水凝胶传感器具有易制备、低成本、高弹性、自发电等优点,为其应用在人造皮肤、人体健康检测以及医疗诊断等领域提供了一定的理论指导依据.

Hydrogel sensors have succeeded in achieving a seamless connection between biology and electronics, but these materials are often plagued by problems such as poor mechanical properties and the need for external power or batteries. In this article, we use polyvinyl alcohol(PVA), acrylonitrile(AN), sodium p-styrene sulfonate(NaSS),acrylamide(AAm) as raw materials, N,N′-methylene bisacrylamide(MBA) as a crosslinker to prepare a polyacrylonitrile-based self-powered hydrogel(PVA-PAN). Its performance was characterized by infrared spectrum,mechanical property test and mechanical-electric response performance test. The results showed that the dipole interaction between the PAN chains and the hydrogen bond between PVA and PAN segments promoted the PAN to the planar zigzag conformation, and the maximum piezoelectric coefficient d_(33)was 32 p/CN. It has a similar young’s modulus value to skin(0.08–5.49 MPa) and good stretchability(97%–408%). Due to the stress-induced polarization effect, the self-powered hydrogel can generate an electrical output of about 60 mV. The V-T curve shows that the hydrogel can accurately detect various human activities(such as joint movement, and step frequency) through the change of voltage signal. In this study, the hydrogel sensor has the advantages of easy preparation, low cost, high elasticity and self-power, which provides theoretical guidance for its application in artificial skin, human health detection, medical diagnosis and other fields.