Enhancing the Sensitivity of Percolative Graphene Films for Flexible and Transparent Pressure Sensor Arrays
Enhancing the Sensitivity of Percolative Graphene Films for Flexible and Transparent Pressure Sensor Arrays
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DOI：
10.1002/adfm.201503674
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发表时间：
2016-07-25
影响因子：
19
通讯作者：
Kong, Jing
中科院分区：
文献类型：
--
作者：
Chen, Zhuo;Ming, Tian;Kong, Jing
柔性和透明的压力传感器阵列可以在许多地方找到应用，例如触摸面板、人造皮肤或人体运动检测。然而，传统的应变计是刚性的且不透明的，并且不适合于这样的应用。基于石墨烯的应变片可以克服这些挑战，但目前仍处于发展的初级阶段。在这项工作中，基于石墨烯的应变片的性能进行了研究，并制定了指导方针，以提高作为传感元件的石墨烯薄膜的耐用性和灵敏度。研究发现，石墨烯薄膜的初始电阻决定了薄膜的规范因子。对于相同的薄膜电阻，发现石墨烯片尺寸和薄膜形态也在确定规范因子中起作用。通过在石墨烯薄片之间组装表面活性剂分子来增加薄片-薄片电阻提供了增强计量因子的额外途径。此外，将反射膜封装在微米薄的聚（甲基丙烯酸甲酯）中不会破坏传感过程，但显着提高了传感器的耐用性。最后，由此增强的石墨烯应变计被集成到柔性和透明的压力传感器阵列中，其表现出高再现性和灵敏度。
Flexible and transparent pressure sensor arrays can find applications in many places such as touch panels, artificial skin, or human motion detection. However, conventional strain gauges are rigid and opaque and are not suitable for such applications. Graphene-based percolative strain gauges can overcome these challenges but currently are still in the infancy of their development. In this work, the performance of graphene-based percolative strain gauges is investigated and guidelines to improve the durability and sensitivity of graphene films as sensing elements are developed. It is found that the gauge factor depends on the initial resistance of the graphene film. For the same film resistance, it is found that graphene flake size and film morphology also play a role in determining the gauge factor. Increasing the flake-flake resistance through assembly of surfactant molecules between graphene flakes provides an additional route to enhance the gauge factor. Furthermore, encapsulating the percolative film in micrometer-thin Poly(methyl methacrylate) does not disrupt the sensing process but significantly improves the sensor's durability. Finally, thus enhanced graphene strain gauges are integrated into flexible and transparent pressure sensor arrays that exhibit high reproducibility and sensitivity.