Smart Materials Electrometer V2.0: Evaluating Piezoresistance in carbon fiber bricks at multiple channels

Abstract

Abstract

Clay-based composites have been emerging as strain-sensors despite the current challenges in incorporating conductive fibers within them. These fibers must resist firing conditions between 900 °C and 1100 °C, which can typically only be withstood by metallic fibers such as steel fibers. Nevertheless, a recent study has demonstrated that graphitic pyroproteins with conductive characteristics can be incorporated into clay-based composites, also known as smart bricks, exhibiting gauge factors comparable to those of carbon/cement-based composites. To evaluate such piezoresistive properties, loading tests in combination with the biphasic approach (10 V at low frequency, <100 Hz) were implemented using a low-cost acquisition system named the Smart Materials Electrometer (SME). This hardware demonstrated significant accuracy in piezoresistive and piezocapacitive measurements in comparison with high-cost systems in the market. In this occasion, a multichannel version of SME (see Figure 1) demonstrated the strain-sensing capabilities of carbon/clay-based bricks. This new generation of smart bricks was embedded in medium-scale walls as piezoresistive sensors to address damage detection and strain-monitoring, paving the way for future applications in structural health monitoring.