Fabrication and Characterization of Self-Sensing Nanocomposite - "Smart Skin"

This study characterizes the behaviour and properties of self-sensing polymer nanocomposite. Specifically, we studied the Electrical, Mechanical and Piezoresistive properties. Electrically the material is conductive with a linear response to change in applied strain. Mechanically the material behaves like a polymer, whose Youngs Modulus increases with added MWCNT. From a piezoelectricalperspective this material is stable and can maintain its electrical and mechanical behaviour for 50 cycles of repeated loading at 2mm/min. When producing thin sheets of nanocomposite, the effects of material thickness on piezoresistivity are negligible. The nanocomposite is fabricated by mechanically mixing multiwalled carbon nanotubes (MWCNT) with 2-part polydimethylsiloxane (PDMS). The randomly aligned MWCNT-PDMS is fabricated for two configurations, Type I and Type II. In these configurations, Type I is read longitudinal to force using 4-Probe method and Type II is read perpendicularly with 2-Probe method. The strain is applied to Type I in tension and Type II in compression. The Type I characterizes the bulk conductivity for varying wt% of MWCNT. The Type II looks at the sheet conductivity for varying thickness.