Piezoresistive Multi-Walled Carbon Nanotube/Epoxy Strain Sensor with Pattern Design

Abstract

Carbon nanotube/polymer-based composites have led to studies that enable the realization of low-cost, high-sensitivity piezoresistive strain sensors. This study investigated the characteristics of piezoresistive multi-walled carbon nanotube (MWCNT)/epoxy composite strain sensors subjected to tensile and compressive loads in one direction at relatively small amounts of strain. A patterned sensor was designed to overcome the disadvantage of the load direction sensitivity differences in the existing sensors. The dispersion state of the MWCNTs in the epoxy polymer matrix with the proposed dispersion process was verified by scanning electron microscopy. An MWCNT/epoxy patterned strain sensor and a patch-type strain sensor were directly attached to an acrylic cantilever beam on the opposite side of a commercial metallic strain gauge. The proposed patterned sensor had gauge factors of 2.52 in the tension direction and 2.47 in the compression direction. The measured gauge factor difference for the patterned sensor was less than that for the conventional patch-type sensor. Moreover, the free-vibration frequency response characteristics were compared with those of metal strain gauges to verify the proposed patch-type sensor. The designed drive circuit compensated for the disadvantages due to the high drive voltage, and it was confirmed that the proposed sensor had higher sensitivity than the metallic strain gauge. In addition, the hysteresis of the temperature characteristics of the proposed sensor is presented to show its temperature range. It was verified that the patterned sensor developed through various studies could be applied as a strain sensor for structural health monitoring.

Novel olive stone biochar particle network for piezoresistive strain sensing in natural fiber‐reinforced composites

“…30 Hwang et al also showed for CNTs in epoxy resin a positive influence of reduced thickness on GF. 71 Meng et al applied a layer of graphene platelets on an elastomer substrate and found out that for thinner graphene layer thickness GF increased. 72 Yu et al printed a polymer 3D network and embedded CNTs in the surface.…”

Multi-Walled Carbon Nanotubes-Based Sensors for Strain Sensing Applications

“…The advantages of using MWCNTs instead of pure ones lie in the additional advantages of the processed materials added to the composites. Scientists have tried different mixed kinds of polymers and nanoparticles to enhance the quality of MWCNT nanocomposite-based sensors [ 102 , 103 , 104 ]. These sensors have proven to have higher sensitivities in terms of G.F., lower response time, and lower hysteresis.…”

Investigation of electrical properties of hybrid nanocomposites containing different fillers on pressure sensor applications under different loading

“…These results verified that MWCNT/epoxy composite sensors could be applied to real-time structural health monitoring. 17 Ku-Herrera and Avilies also focused on the piezoresistive behavior of MWCNT/vinyl ester composites under axial tension and compression for use in structural health monitoring and smart detection systems. They found that the piezoresistive behavior of the composite material was linear and reversible in tension for all levels of applied strain since the vinyl ester thermosetting matrix was brittle in tension.…”