Sensitive electromechanical sensors using viscoelastic graphene-polymer nanocomposites

Abstract

Despite its widespread use in nanocomposites, the effect of embedding graphene in highly viscoelastic polymer matrices is not well-understood. We add graphene to a lightly crosslinked polysilicone, often encountered as Silly Putty, changing its electro-mechanical properties significantly. The resulting nanocomposites display unusual electromechanical behavior such as post-deformation temporal relaxation of electrical resistance and nonmonotonic changes in resistivity with strain. These phenomena are associated with the mobility of the nanosheets in the low-viscosity polymer matrix. By considering both the connectivity and mobility of the nanosheets, we develop a quantitative model that completely describes the electromechanical properties. These nanocomposites are sensitive electromechanical sensors with gauge factors >500 which can measure pulse, blood pressure and even the impact associated with the footsteps of a small spider.

Synthesis of Zirconium-Containing Polyhedral Oligometallasilsesquioxane as an Efficient Thermal Stabilizer for Silicone Rubber

“…Silicone rubber (SR) is widely used as encapsulation adhesive, sealant, and heat-insulating coating in the field of electronics and aerospace because of its excellent high-temperature resistance, ozone resistance, and electrical insulation [1][2][3]. SR maintains good service performance under 250 • C for a long time.…”

EPR and Impedance Measurements of Graphene Oxide and Reduced Graphene Oxide

“…Even very slight stress change, e.g. due to the flow of blood in veins can be detected by measuring the electrical conduction of the graphene-based sensor [12]. This problem is very close to our previous work on the control of conducting properties via modifications of connections between the graphite-like nanoparticles in ACFs [7,9].…”

Printing Polymer Nanocomposites and Composites in Three Dimensions

“…[1][2][3] There exist various types of nanomaterials including, but not limited to, carbon nanotubes, carbon nanofibers, graphene, metallic nanowires, metallic and ceramic nanoparticles, clay nanoplatelets, and quantum dots. The incorporation of these nanomaterials into polymers enables the fabrication of entirely new materials, called polymer nanocomposites that exhibit unique properties or functionality (e.g., electrical and thermal conductivities, [4] electro-mechanical sensitivity, [5] magnetism, [6] and mechanical strength [7] ). For instance, electrically conductive nanomaterials such as silver nanoparticles, copper nanowires, and graphene are used to enhance the overall conductivity of relatively insulating polymers for a broad range of potential applications.…”

“…For instance, electrically conductive nanomaterials such as silver nanoparticles, copper nanowires, and graphene are used to enhance the overall conductivity of relatively insulating polymers for a broad range of potential applications. [5,8] The nanomaterials, as nanofillers, not only help improve various properties of polymers, they may also help overcome fabrication and manipulation constraints related to the small size of nanomaterials. [9] In addition, the nanomaterials can be used as fillers to tailor rheological behavior of polymer materials in order to make them suitable for processing where needed.…”