摘要
Potassium sodium niobate(KNN)-based nanofibers could combine piezoelectric properties with exceptional flexibility and biocompatibility,making them highly promising for flexible sensors in electronic skin and wearable applications.However,the suboptimal piezoelectric performance limits their sensitivity in detecting minute human body motions,such as blinking and eye movements.Herein,Li and Ta-doped KNN nanofibers were fabricated via an electro-spinning process.Co-doping with 6%Li at the A-site and 30%Ta at the B-site induces lattice distortion and an orthorhombic(O)to tetragonal(T)phase transition in the electrospun nanofibers,resulting in a significantly enhanced piezoelectric response,with an average d_(33)*value reaching 110.7 pm/V.The outstanding piezoelectric response gives rise to a remarkable sensitivity(0.3365 V/(N cm^(2)))in a self-powered flexible pressure sensor based on the doped KNN nanofibers,encapsulated in a polydimethylsiloxane matrix.The sensors,when attached to the temple regions,can detect tiny facial motions induced by blinking,enabling the distinction of abnormal blinking patterns associated with mental fatigue and excessive eye use.Additionally,they support real-time,continuous,and unobtrusive eyeball tracking,highlighting their potential as critical components in human-computer interaction and artificial intelligence applications.
铌酸钾钠(KNN)基纳米纤维兼具高压电响应、柔性和生物相容性,在电子皮肤和可穿戴器件等领域具有巨大的应用潜力,但其有限的压电性能制约了其检测眨眼、眼球转动等微小人体运动的灵敏度.本文采用静电纺丝法制备了Li和Ta掺杂的KNN纳米纤维.对A位和B位的Li、Ta共掺杂引起了晶格畸变和正交(O)-四方(T)相变,显著增强了材料的压电响应,其平均压电常数d_(33)*达到110.7 pm/V.得益于掺杂KNN纳米纤维的优异压电响应,将其进行PDMS封装所得的柔性自供电传感器表现出良好的压力传感灵敏度(0.3365 V/(N cm^(2))).将该传感器简单贴敷于太阳穴附近,可检测因眨眼动作而造成的微小皮肤形变,可用于识别因精神疲劳或用眼过度而造成的异常眨眼行为.该器件还可实现实时、连续和非侵入性地眼球跟踪功能,在人机交互和人工智能等领域显示出应用潜力.
基金
financially supported by the National Natural Science Foundation of China(U21A20500 and 52072115)
the Natural Science Foundation(Outstanding Youth Project)of Hubei Province(2023AFA074)
the Postdoctoral Fellowship Program of CPSF(GZC20230744)
the Postdoctoral Innovation Research Program in Hubei Province(352899)。
