Du Zhengyang, Chen Ji'an, Liu Chang, Jin Chen, Han Min
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Materials (Basel). 2020 Oct 29;13(21):4838. doi: 10.3390/ma13214838.
We use gas phase deposition of well-defined nanoparticles (NPs) to fabricate closely-spaced Pd NP arrays on flexible membranes prepatterned with interdigital electrodes (IDEs). The evolution of the morphology and electron conductance of the NP arrays during deposition is analyzed. The growth of two-dimensional percolation clusters of interconnected NPs, which correlate with the percolation pathway for electron conduction in the NP deposits, is demonstrated. The percolative nature of the NP arrays permits us to finely control the percolation geometries and conductance of the NP film by controlling the NP deposition time so as to realize a precise and reproducible fabrication of sensing materials. Electron transport measurements reveal that the electrical conductance of the NP films is dominated by electron tunneling or hopping across the NP percolating networks. Based on the percolative and quantum tunneling nature, the closely-spaced Pd NP films on PET membranes are used as flexible strain sensors. The sensor demonstrates an excellent response ability to distinguish tiny deformations down to 5×10 strain and a high sensitivity with a large gauge factor of 200 up to 4% applied strain.
我们使用气相沉积法制备定义明确的纳米颗粒（NP），以在预先用叉指电极（IDE）图案化的柔性膜上制造紧密排列的钯纳米颗粒阵列。分析了沉积过程中纳米颗粒阵列的形态和电子电导的演变。展示了相互连接的纳米颗粒二维渗流簇的生长，这与纳米颗粒沉积物中电子传导的渗流途径相关。纳米颗粒阵列的渗流特性使我们能够通过控制纳米颗粒沉积时间来精细控制纳米颗粒膜的渗流几何形状和电导，从而实现传感材料的精确且可重复制造。电子输运测量表明，纳米颗粒膜的电导主要由电子隧穿或跨越纳米颗粒渗流网络的跳跃主导。基于渗流和量子隧穿特性，聚对苯二甲酸乙二酯（PET）膜上紧密排列的钯纳米颗粒膜被用作柔性应变传感器。该传感器表现出出色的响应能力，能够区分低至5×10应变的微小变形，并且在高达4%的施加应变下具有高达200的大应变系数的高灵敏度。
