Highly stretchable and sensitive strain sensor based on a simple friction-transfer method

Stretchable strain sensors that can detect and monitor human motion have attracted enormous attention in the field. To realize fully the translation of materials for stretchable strain sensors, it is important to make the fabrication way less complex and lessen the production cost. This paper investigated low-cost graphite-VHB strain sensors prepared by simple friction-transfer method. Designed by friction-transfer method, the graphite-VHB strain sensor possesses good flexibility, light weight, high stretchability and tunable range of GF. The gauge factor of the sample was 20 when strain rate was 3% and could be over 1000 when the strain rate was 50%. The addition of protection layer and pre-aging process have contributions to expand the GF of the sample. By attaching our strain sensor to the sample of mechanical arm, the resistance change of the sensor perfectly fitted to the deformation of the arm, which shows its potential in application of soft robotics and mechanical fields. The results showed the friction-transfer method is a simple and low-cost method, featured with environmental advantage that avoids chemical wastes.