Flexible Strain Sensors Based on Pentacene-Carbon Nanotube Composite Thin Films

In this study, we present the first flexible strain sensors based on pentacene-carbon nanotubes (CNTs) composite thin films employing a Wheatstone bridge configuration. The sensors were characterized with bending at 0, 45, and 90 degrees with respect to the bridge bias direction, applying strains of 1, 1.25, 1.67, and 2.5 ‰, respectively. It was noted that the output signal of the sensors is substantially enhanced with the addition of CNTs, resulting from the improvement in conductivity of the sensing active layer. This strain sensor using the CNTs-organic semiconductor matrix composite thin films as the active layer fabricated on flexible substrates is expected to possess better reliability as compared with conventional metallic foils and inorganic semiconductor strain sensors because of their low Young's modulus (~5GPa).