Controllable Fabrication of Percolative Metal Nanoparticle Arrays Applied for Quantum Conductance-Based Strain Sensors.

Zhengyang Du,Chen Jin,Chang Liu,Ji’An Chen,Min Han

doi:10.3390/ma13214838

Zhengyang Du, Chen Jin + Show 3 more

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https://doi.org/10.3390/ma13214838

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Abstract

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 5×10−4 strain and a high sensitivity with a large gauge factor of 200 up to 4% applied strain.

Highlights

Strain and pressure sensors are important micro-electro-mechanical system (MEMS) devices, with applications in various areas such as industrial control, automotive and aerospace systems, consumer electronics, environmental monitoring and wearable devices and electronic skins [1,2,3,4].To achieve strain and pressure gauging, a number of transduction mechanisms including capacitive, piezoelectric, piezoresistive, as well as transistor sensing have been utilized
Results and Discussion strains were induced by subjecting the polyethylene terephthalate (PET) membranes to a series of bending cycles or pull-andrelease cycles driven with a micrometer
In the pull-and-release case, one of the PETwith slicediameters was fastened on the of see the NP assemblies are mainly composed of aside group of NPs between

Summary

Introduction

Strain and pressure sensors are important micro-electro-mechanical system (MEMS) devices, with applications in various areas such as industrial control, automotive and aerospace systems, consumer electronics, environmental monitoring and wearable devices and electronic skins [1,2,3,4].To achieve strain and pressure gauging, a number of transduction mechanisms including capacitive, piezoelectric, piezoresistive, as well as transistor sensing have been utilized. Conductive polymer composites incorporating conductive fillers such as carbon blacks, nanoparticles (NPs), nanotubes, as well as graphene membranes in/on an insulating polymer matrix have been used as strain/pressure sensing elements [8,9,10,11,12,13,14,15,16]. Strains applied on these composites may cause a drastic fall in resistivity due to the formation of percolation paths [15]

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