FABRICATION OF HIGHLY FLEXIBLE STRAIN SENSOR BASED ON ELASTOMER/MXene COMPOSITES

Abstract

Flexible strain sensor has gained popularity in recent years due to high demand in modern applications such as flexible electronics, IoT, human-machine interactions, human-motion detection and structural health monitoring. Usually, metal layers made of silver, copper and other metals were deposited to create strain sensors. Nevertheless, they are frequently made from non-stretchable substrates, they have a restricted ability to be elongated for large strains; therefore, they are not durable at large strain range and are susceptible to mechanical faults. In the present work, we investigate the fabrication of a highly flexible strain sensor based on ternary composites; PDMS/MXene/CNTs composite. MXene (2D material) and multi-walled carbon nanotubes (MWCNTs, 1D material) are added via solution mixing as conductive nanofillers into a flexible matrix; poly(dimethylsiloxane). X-ray diffraction, Raman spectra and scanning electron microscopy are employed to study chemical morphology and microstructure of the developed film. Gauge factor – sensitivity to mechanical strain− is recorded as high as 7. The developed sensor was durable and reliable with no significant deterioration over 103 cycle. Sensing various human movements is also investigated showing high sensitivity to elbow bending, and knee and wrist movements. The study shows that integrating 2D and 1D materials as two-phase conductive nanofillers is a promising strategy to develop highly strain-sensitive and yet flexible nanocomposites.