Institute of Chemical Engineering Sciences, Foundation of Research and Technology Hellas, Platani St., 26504 Patras, Greece.
Department of Chemical Engineering, University of Patras,1 Karatheodori St., 26504 Patras, Greece.
Nanotechnology. 2023 May 2;34(29). doi: 10.1088/1361-6528/acccfe.
Graphene and other two-dimensional materials (2DMs) have been shown to be promising candidates for the development of flexible and highly-sensitive strain sensors. However, the successful implementation of 2DMs in practical applications is slowed down by complex processing and still low sensitivity. Here, we report on a novel development of strain sensors based on Marangoni self-assemblies of graphene and of its hybrids with other 2DMs that can both withstand very large deformation and exhibit highly sensitive piezoresistive behaviour. By exploiting the Marangoni effect, reference films of self-assembled reduced graphene oxide (RGO) are first optimized, and the electromechanical behaviour has been assessed after deposition onto different elastomers demonstrating the potential of producing strain sensors suitable for different fields of application. Hybrid networks have been then prepared by adding hexagonal boron nitride (hBN) and fluorinated graphene (FGr) to the RGO dispersion. The hybrid integration of 2D materials is demonstrated to become a potential solution to increase substantially the sensitivity of the produced resistive strain sensors without compromising the mechanical integrity of the film. In fact, for large quasi-static deformations, a range of gauge factor values up to 2000 were demonstrated, while retaining a stable performance under cyclic deformations.
石墨烯和其他二维材料（2DMs）已被证明是开发柔性和高灵敏度应变传感器的有前途的候选材料。然而，2DMs 在实际应用中的成功实施受到复杂加工和仍然较低的灵敏度的限制。在这里，我们报告了一种基于石墨烯及其与其他 2DMs 的混合物的 Marangoni 自组装的新型应变传感器的发展，该传感器既可以承受非常大的变形，又具有高灵敏度的压阻行为。通过利用 Marangoni 效应，首先优化了自组装还原氧化石墨烯（RGO）的参考膜，并在沉积到不同弹性体上后评估了其机电行为，证明了生产适用于不同应用领域的应变传感器的潜力。然后通过向 RGO 分散体中添加六方氮化硼（hBN）和氟化石墨烯（FGr）来制备混合网络。混合集成二维材料被证明是提高所制备的电阻应变传感器灵敏度的一种有前途的解决方案，同时不会影响薄膜的机械完整性。事实上，对于大的准静态变形，证明了高达 2000 的范围的应变系数值，同时在循环变形下保持稳定的性能。
