Biomimetic flexible strain sensor with high linearity using double conducting layers

Herein, inspired by the structure of lateral line scale, which is a sensory organ of fish, a biomimetic flexible fiber strain sensor is proposed. This sensor was designed using a simple and controllable layer-by-layer dip coating process to construct double conducting layers in a cylindrical sandwich structure. Additionally, a novel structure of conducting-medium-substrate was used for the fiber strain sensor via the introduction of modification layer. The biomimetic strain sensor exhibits sensing characteristics of dynamic response, gauge factor (GF) (~2.0 for 50% strain) fast response time (~60 ms), and long-term durability over 3000 cycles. Furthermore, ultrahigh linearity of R 2 ＞0.992 (adjusted R-squared) or δ <10% (nonlinear error) (the linear trend is valid both for stretch and release up to 50% strain) for the strain sensor was realized owing to the sensing mechanism of double conducting layers based on the bioinspired design. Our flexible strain sensors with double conducting layers can provide ideas for the design of novel bionic flexible devices. Furthermore, its application in wearable electronics, human-computer interaction, dexterous hand master-slave system, and robot teleoperation is promising.