Comparison of flexible strain sensors based on liquid metals with different microchannel structures

Abstract Flexible strain sensors based on fluid microchannels have been widely used in flexible electronics due to their excellent performance. However, the current research ignores the effect of different microchannel structures on the performance of flexible sensors, which is unsuitable for a specific practical application. Therefore, in this paper, sensors with microchannel of straight, wavy, and triangular structures were developed, and the performances of these sensors were compared from the results of simulation and experiment, respectively. The results show that the flexible strain sensors based on these three microchannels have extremely low hysteresis performance. Compared to the strain-stress hysteresis of the straight and wavy sensors, triangular sensors have the lowest hysteresis about 1.713%. Consistently, the triangular sensors also have the lowest hysteresis about 0.229% under strain-resistance response among these sensors. However, the straight sensors have the highest sensitivity among them. In different angles of the same microchannel group, the 180-degree wavy and 90-degree triangular sensors have the lowest hysteresis. Finally, the 90-degree triangular sensor was successfully used to detect the motion states of the human body and robotic finger. The research in this paper provides new ideas for choosing which microchannel of flexible strain sensors to be used in the field of wearable electronics.