Research Information System
Journal of Materials Science: Materials in Electronics, vol.34, no.35, 2023 (SCI-Expanded)
This study focuses on improving the performance parameters of nanocomposite-based pressure sensors to ensure comfortable use. Here, nanocomposite-based active sensing materials were screen-printed on cotton fabric. Functionalized carbon nanotubes (fCNTs), graphene nanoplatelets (GNPs) and silver nanoparticles (Ag NPs) were utilized with polyvinyl alcohol (PVA) to produce the nanocomposites to be used as the sensing layer. The sensors were studied in terms of frequency response, percolation threshold, sensitivity, durability and response-recovery speed. The outcomes indicate that all fabricated sensors are highly capacitive when no pressure is applied. However, as the pressure increases, the sensors favor resistive responses. This rapid variation in the phase angle allows sensing of touch or pressure. Furthermore, frequency response analyzed in 100 Hz–25 MHz range under pressure revealed that fCNT-based and GNP-based sensors switched from piezoresistive to capacitive sensing after almost 80 kHz and a similar change occurred for Ag NP-based sensor after 1 MHz. Considering impedance responses rather than only capacitive or piezoresistive measurements provides more information, and allows us to evaluate the tactile sensors in a frequency range. This finding is critical to enable the sensor to be used with different sensing mechanisms in specific frequency ranges.