State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Collaborative Innovation Center of Polymers and Polymer Composites , Fudan University , 2005 Songhu Road , Shanghai 200438 , China.
Department of Industrial Design , Eindhoven University of Technology , P.O. Box 513, Eindhoven 5600 MB , The Netherlands.
ACS Appl Mater Interfaces. 2019 Feb 27;11(8):8527-8536. doi: 10.1021/acsami.8b20902. Epub 2019 Feb 15.
Constructing flexible, high-sensitivity strain sensors with large working ranges is an urgent task in view of their widespread applications, including human health monitoring. Herein, we propose a self-compensated two-order structure strategy to significantly enhance the sensitivity and workable range of strain sensors. Three-dimensional printing was employed to construct highly stretchable, conductive polymer composite open meshes, in which the percolation network of graphene sheets constitutes a deformable conductive path. Meanwhile, the graphene layer coated on the open mesh provides an additional conductive path that can compensate spontaneously for the conductivity loss of the percolation network at large strains, through new conductive paths formed by the graphene sheets in the coating layer and the inner networks. At strains lower than 20%, the sliding and disconnection of graphene sheets coated on the mesh surface largely enhance the sensitivity of the sensor, a 20 times increase as opposed to that of the non-two-order structure sensor. The resulting sensor reveals high gauge factors (from 18.5 to 88 443) in a strain range of 0-350% and the exceptional capability to monitor a wide range of human motions, from the subtle pulse, acoustic vibration to breathing and arm bending.
构建具有大工作范围的灵活、高灵敏度应变传感器是当务之急，因为它们的应用广泛，包括人类健康监测。在此，我们提出了一种自补偿二阶结构策略，以显著提高应变传感器的灵敏度和工作范围。通过三维打印构建了高可拉伸的导电聚合物复合开放式网格，其中石墨烯片的渗流网络构成了可变形的导电路径。同时，涂覆在开放式网格上的石墨烯层提供了一个额外的导电路径，可以通过涂覆层和内部网络中的石墨烯片形成的新导电路径，自发补偿大应变下渗流网络的电导率损失。在应变低于 20%时，涂覆在网格表面的石墨烯片的滑动和断开大大提高了传感器的灵敏度，比非二阶结构传感器的灵敏度提高了 20 倍。由此产生的传感器在 0-350%的应变范围内具有较高的应变系数（从 18.5 到 88443），并且具有监测广泛人体运动的出色能力，从微妙的脉搏、声振动到呼吸和手臂弯曲。
