# Conductive Textiles for Signal Sensing and Technical Applications
## 5 Application of Conductive Textiles
### Soft Robotics  
Soft robotics is a branch of robotics that involves constructing robot bodies and actuators using extremely soft or expansible materials [315]. Future soft actuation technologies could utilize conductive textiles as electrode materials of sensing transducers that can be resistive or piezoresistive with a wide variety of sensing functionality, including shape reconstruction, bending angle, direction, contraction length, or circumference [316]. Conductive yarns demonstrate electric actuation by changing the distance of twisted fibers by electromagnetic or electrostatic force [317]. A PVC gel-based actuator comprised of a PVC inner core and insulated PVC shell was designed. A pair of identical fibers that were loosely twisted together got closer together and resulted in the elongation of yarn when voltage was applied to the two fibers' inner cores. A textile-type and a yarn-type actuator were constructed, and a maximum contraction strain of 53% and an expansion ratio of 1.4% were achieved, respectively [318]. A planer DE (Dielectric Elastomer) actuator, bending DE actuator, and EA (electro-adhesive) actuator have been developed and tested. Under 9 kV and 6 kV, relative expansion rates of 16.4% and 5% were achieved for the planer and bending DE actuators, respectively. Additionally, under 5 kV, the shear adhesive of 0.14 kPa was obtained for the EA actuator. Furthermore, a crawling robot driven by the above actuators has been developed, traveling 18 mm distance in 3 min [319]. An octopus-inspired continuum robot arm was constructed based on a conductive textile material called Electrolycra (Mindsets Ltd., Saffron Walden, UK) [320]. A bending sensor was developed for a robotic glove in which a dielectric silicone was employed as the sensing material, which was placed between conductive knitted electrodes manufactured from silver-coated yarn.  
Additionally, the sensor mat was set parallel to the Wales structure, which was sounded with extra silicone [321]. [PERSON] et al. designed a new shape-sensing system based on electroconductive yarn material integrated into a soft manipulator with pneumatic actuation, which is suitable for implementation in miniature surgical instruments [321]. [PERSON] et al. built an artificial muscle with actuating and sensing functions [322]. The bimorph tendril-like fiber was created by thermally pulling cyclic olefin co-polymer elastomer and polyethylene. As a resistance strain sensor, a coating of conductive nanowire mesh was applied to the fiber. The fiber contracted as it was heated, and the electrode's resistance monitored the contraction and elongation based on piezoresistive feedback.  
Furthermore, a humanoid limb was fitted with sensor-fitted fiber actuators. When heated with a hot gun, the fiber actuators contracted, causing the artificial limb to bend, and the resistance change of the electrodes was used to determine the bending angle of the limb [317]. A highly stretchable and durable conductive knitted fabric was developed and applied to the covering of a paper-fabric composite-based actuator, which has the potential as the electronic skin of soft robots. The electrical resistance of the fabric was sustained under a maximum average membrane strain of 300% in 3D deformation. The fabric was capable of withstanding more than 1,200,000 cycles of loading under 20% tensile strain and 10,000 abrasion cycles [323].