Triboelectric nanogenerator-powering piezoresistive cement-based sensors for energy harvesting and structural health monitoring

Abstract

Piezoresistive cement-based pressure sensors can detect traffic flow and structural changes in concrete structures. However, their reliance on significant external energy inputs limits practical adoption. This study develops an integrated cement-based device that implies a cement-based triboelectric nanogenerator (TENG) to harvest mechanical energy and power the piezoresistive cement-based sensor through a specially designed circuit, enabling electrical resistance monitoring under external mechanical loads. The device determines the fractional changes of resistivity (FCR) by analysing current changes in two separate branches. The optimized 1.0 wt% graphene nanoplates (GNP) incorporated into cementitious composites enhance electrical conductivity and the dielectric constant, while excessive GNP reduces impedance and dielectric properties. The resulting TENG achieves a short-circuit current of 7.0 µA and a peak-to-peak open-circuit voltage of 330 V. The piezoresistive sensor exhibits repeatable, reversible, and sensitive performance under high-range static and low-range dynamic loads. The force and FCR measurements recorded by the integrated device under various mechanical stimulations closely match the calculated results. This work advances the development of self-powering cement-based sensors without external energy inputs for traffic condition detection and structural health monitoring.