Unidirectional, highly linear strain sensors with thickness-engineered conductive films for precision control of soft machines†
Current stretchable strain sensors possess limited linear working ranges and it is still a formidable challenge to develop sensors that concurrently possess high gauge factors and high stretchability (ε ∼100%). Herein, we report a facile method for creating unidirectional strain sensors to address the above issues. Using the 3D printing technique, we introduced thickness variations to control microcracking patterns in a carbon nanofibers-containing PEDOT:PSS thin-film sensor. As a result, the sensor is capable of exceptionally linear response for up to 97% tensile strain while maintaining a high gauge factor of 151.