Yang Tingting, Wang Wen, Huang Yuehua, Jiang Xin, Zhao Xuanliang
Tribology Research Institute, School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China.
College of Engineering and Technology, Southwest University, Chongqing 400715, China.
ACS Appl Mater Interfaces. 2020 Dec 23;12(51):57352-57361. doi: 10.1021/acsami.0c16855. Epub 2020 Dec 10.
Sensitivity and linearity are two key parameters of flexible strain sensors. Although the introduction of microstructures (, channel crack inspired by the geometry of the spider's slit organ) can effectively improve the sensitivity, the sudden breakage of the conductive path in turn leads to poor linearity. In practical applications, in order to achieve precise detection of subtle strains, high sensitivity and high linearity are required simultaneously. Here, we report a strain sensor design strategy based on the ductile fragmentation of functionalized graphene multilayers (FGMs) in which the conductive path is gradually broken to ensure high sensitivity while greatly improving the linear response of the sensor. The presence of oxygen-containing functional groups plays a key role in the deformation and fracture behaviors of the sensitive layer. High sensitivity (gauge factor ∼ 200) and high linearity (adjusted -square ∼ 0.99936) have been achieved simultaneously in the strain range of 0-2.5%. In addition, the sensor also shows an ultralow detection limit (ε < 0.001%), an ultrafast response (response time ∼ 50 μs), good stability, and good patterning capability compatible with complex curved surface manufacturing. These outstanding performances allow the FGM-based strain sensors to accurately distinguish the sound amplitude and frequency, highlighting the sensor's potential as smart devices for human voice detection. Such sensors have potential applications in the fields of smart skin, wearable electronics, robotics, and so on.
灵敏度和线性度是柔性应变传感器的两个关键参数。尽管引入微观结构（例如，受蜘蛛缝器官几何形状启发的通道裂纹）可以有效提高灵敏度，但导电路径的突然断裂反过来会导致线性度较差。在实际应用中，为了实现对细微应变的精确检测，需要同时具备高灵敏度和高线性度。在此，我们报告一种基于功能化石墨烯多层膜（FGMs）韧性破碎的应变传感器设计策略，其中导电路径逐渐断裂，以确保高灵敏度，同时极大地改善传感器的线性响应。含氧官能团的存在在敏感层的变形和断裂行为中起关键作用。在0-2.5%的应变范围内同时实现了高灵敏度（应变片系数约为200）和高线性度（调整后平方约为0.99936）。此外，该传感器还显示出超低检测限（ε<0.001%）、超快响应（响应时间约为50μs）、良好的稳定性以及与复杂曲面制造兼容的良好图案化能力。这些优异性能使基于FGM的应变传感器能够准确区分声音的幅度和频率，突出了该传感器作为人类语音检测智能设备的潜力。此类传感器在智能皮肤、可穿戴电子设备、机器人技术等领域具有潜在应用。
