Silicon-based strain gauge sensors embedded in composite structures for real-time strain and creep analysis

Abstract. This study demonstrates how integrating silicon mechanical sensors into composite structures enables the detection of internal structural variations and can find applications in process monitoring or structural health monitoring (SHM). It introduces a novel, minimally intrusive process for embedding sensors within composites (substrate-free transfer-printed sensor). Both temperature and strain effects are studied and presented. The silicon strain sensor exhibits high sensitivity due to the piezoresistive effect. The combination of high temperature and strain produces a plastic degradation of the material, linked to the creep phenomenon of the composite's epoxy resin binder. This internal structure modification in the composite is directly detected with the strain gauges in real time.