Super-elastic ultrasoft natural rubber-based piezoresistive sensors for active sensing interface embedded on soft robotic actuator

1Super-elastic, ultrasoft natural rubber based piezoresistive sensor containing multiwalled carbon nanotubes in presence of hydrofinished oil-based softener.2Sensor exhibits low electrical percolation, ultra-softness, elastic modulus in the kPa range, ultra-stretchability and high tensile strength.3The state-of-the-art strain sensor possesses low hysteresis, high piezoresistive sensitivity, stability and switching response over wide strain range.4Sensing strip embedded on a soft robotic pneumatic actuator mounted on a test rig showed excellent movement detection response upon actuation.5Sensor is capable of detecting mild-to-strong physiological human motion with high repeatability and sensitivity. Piezoresistive soft composites are ubiquitous in strain sensing that manifests in a dramatic increment of electrical resistivity upon elongation. A piezoresistive strain sensor embedded-soft robotic arm has been a challenging task in terms of surface compatibility, shape and dynamics of the soft robotic components. We present a super-elastic, ultrasoft natural rubber composite containing multiwalled carbon nanotubes in presence of a hydrofinished oil-based softener. The resulting conducting elastomer offered a line-up of compelling characteristics such as low electrical percolation (1000). On account of the excellent responses mentioned, the sensor could detect human motion and has also been demonstrated in this paper. Furthermore, the sensing strip embedded on a soft robotic pneumatic actuator mounted on a test rig showed excellent movement detection response upon actuation. This proof-of-concept sensor-integrated soft robotic interface could be instrumental in the future development of proprioceptive sensing robots and soft robotic segments. [Display omitted]