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Fabrication of flexible piezoresistive sensors based on RTV-silicone and milled carbon fibers and the temperature´s effect on their electric resistance

2019; Elsevier BV; Volume: 302; Linguagem: Inglês

10.1016/j.sna.2019.111811

1873-3069

Carlos-Manuel Sánchez-González, Juan F. Soriano, J Rubio-Avalos, J. Jesús Pacheco Ibarra,

Analytical Chemistry and Sensors

Flexible robotics and smart wearable technologies are under intensive research due to their potential applications. Flexible sensors that are an essential part of these systems are mainly made of a soft polymer matrix and an electric conductive reinforcement. However, when a flexible sensor is heated or an electric current is applied a joule heating effect is produced rising the material´s temperature, and since soft polymers are temperature-sensitive there is a change in their physical dimensions, giving as a result, a dramatic change in their electric properties. This work contributes to a better understanding of the temperature´s effect on the piezoresistive properties of these sensors, (i.e.) the electric resistance of some sensors changed from ohms at room temperature to Mega-ohms at 80 °C, these change were possible due to an excellent thermal conductivity and heat distribution of the flexible resultant composites, as well as, the physical expansion of the polymer matrix reducing the milled carbon fibers´ interconnectivity and increasing the potential barrier between them.