Ultra‐High Gauge Factor Strain Sensor with Wide‐Range Stretchability

Abstract

Strain sensors with wide‐range stretchability, good sensitivity, high gauge factor, and reliability are needed for several applications. Herein, stretchable strain sensors capable of operating over multi‐strain range and having an excellent gauge factor are presented. The systematic study, carried out with different combinations of elastomer, conductive filler, and graphene–carbon paste (GCP), revealed that the sensors exhibit excellent stretchability when only filler particles are present in the elastomer, and they exhibit high sensitivity when filler particles are mixed with GCP. The molecular dynamics simulations show that the addition of GCP to the elastomer‐filler composite helps to attain an excellent sensor response with wide range stretchability. Thus, sensors’ response can be tuned by using selected material composition. Accordingly, the strain sensor with 50 wt% GCP reveals 500% stretchability and a maximum gauge factor of 504. Likewise, 150 wt% GCP loading lead to sensors with 45% stretchability and an unprecedented gauge factor of 1 834 140. The capability to detect the small‐ to large‐scale strains makes the presented sensors attractive for monitoring the movements of body parts–which range from small movements during facial expression to large movement experienced by the limb joints.

Keywords

• carbon nanotubes
• elastomer and gauge factor
• strain sensors
• stretchable electronics