Highly stretchable printed strain sensors using multi-walled carbon nanotube/silicone rubber composites

The developing fields of wearable electronics and soft robotics have created a strong demand for flexible and stretchable strain sensors. This work presents a printing technique and conductive multiwalled carbon nanotube/silicone polymer nanocomposites applied to achieve embedded piezoresistive large strain sensors. A printing process that allows the sensors to be produced inside a silicone substrate has compelling advantages: fabricated devices are well insulated and protected against wear. These process features simplify fabrication of complex patterns. Printed sensors can withstand stretching of up to 300%, with maximum hysteresis of 11% for 300% maximum strain, and gauge factors between 1.0 and 1.5 depending on the selected composition. The devices developed in this work have potential applications in the measurement of human body motion and position control of soft actuators.