초록 |
One of the important features for future strain sensors is that they should be able to sensitively recognize the direction of the external stress in order to accurately detect the motions of humans or matter. Herein, we successfully developed a directionally responsive piezoresistive strain sensor whose sensing electrode was made of CNTs and designed in the shape of an asterisk. Under a given stress at 5 % strain, the change in relative resistance (ΔR/R0) of the strain sensor developed here differed by up to a factor of 24.5 for different orientations of the sensor electrode relative to the source of the stress, i.e., a high angular dependence of the sensing performance on the external stress direction was observed. In particular, the asterisk-shaped CNT strain sensors showed a super-linear relationship between response and strain for low strains of up to 5 %, allowing them to provide a good sensing platform for recognizing micro-deformations. |