Unveiling the potential of a sustainable source biochar in flexible temperature sensor fabrication

Abstract This study unveils a novel composite material for flexible temperature sensor applications, marking a significant step forward in the field of materials science and engineering. The conductive fillers, graphite, and biochar were used in various concentrations, along with the sodium silicate solution, which served as the matrix material. The fluid nature of the sodium silicate solution makes it optimal for screen and inkjet printing techniques. Composites with varying concentrations of graphite and biochar were prepared and deposited on a flexible substrate. Percolation and co-percolation studies were conducted. The electrical, chemical, morphological, and structural properties of the raw materials and composites were characterized using a Hall effect device, Raman spectroscopy, scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy, an X-ray diffractometer (XRD), and digital multimeters. The impact of conductive filler concentrations and the synergistic effect of graphite and biochar on sensor performance were investigated and compared, revealing innovative and promising results. The results show that biochar-based samples were superior to graphite-based samples in terms of good repeatability, better long-term stability, and response time. The combination of graphite and biochar also positively affected sensor performance in terms of sensor stability.