Stretchable conducting gold films prepared with composite MWNT/PDMS substrates

Abstract

Novel stretchable conducting films were prepared by depositing gold layers onto polymer nano-composites substrates formed by in-situ crosslinking of polydimethylsiloxane (PDMS) in the presence of multiwall carbon nanotubes (MWNT). The MWNT content interferes with the PDMS cure reaction giving variations in thermal degradation, solvent swelling, mechanical and electrical properties. Tensile cycling experiments were carried out on the gold-coated PDMS and nano-composite substrates SEM analysis and electrical measurements demonstrated that the crack widening and increased electrical resistance observed during strain cycling were reversible. The inclusion of 8 % MWNT into PDMS brought more micro-cracking in the gold layer yet reduced the electrical resistance of the gold-coated samples by 172X at 5 % strain, 38X at 10 % strain and 19X at 20 %. Hence, this improvement in conduction is attributed to assisted-conduction through the MWNT loaded substrate. This mechanism results in a more stable and reproducible electrical behaviour, making electrical conduction less critically dependent on defects in the gold layer.

Nanocomposite-Based Microstructured Piezoresistive Pressure Sensors for Low-Pressure Measurement Range

“…As described in detail in the next paragraph, the preparation process of the MWCNT/PDMS involves multiple dispersion steps utilising ultrasonication, an organic solvent and mechanical stirring as in [ 38 , 39 , 40 , 41 , 42 , 43 ], to achieve a uniform distribution of the MWCNT filler particles within the elastomeric matrix and facilitate an isotropic composite conductivity. Due to the strong inter-tube Van der Waals attractive forces, CNTs form together highly aggregated agglomerates in their natural state and hence external mechanical energy is required to separate these aggregates [ 44 , 45 , 46 , 47 ].…”

3D‐Structured Stretchable Strain Sensors for Out‐of‐Plane Force Detection

“…The result shows that the resistance change is much smaller (only ~ 18%) and the repeatability is also poor, and our observation is consistent with previously reported results. [71] The as-prepared 3D-structured stretchable strain sensor is presented in Figure 2b. As investigated before, the in-plane SWCNT film possesses full stretchability.…”