Evaluation of different conductive nanostructured particles as filler in smart piezoresistive composites

This work presents a comparison between three piezoresistive composite materials based on nanostructured conductive fillers in a polydimethylsiloxane insulating elastomeric matrix for sensing applications. Without any mechanical deformation upon an applied bias, the prepared composites present an insulating electric behavior, while, when subjected to mechanical load, the electric resistance is reduced exponentially. Three different metal fillers were tested: commercial nickel and copper spiky-particles and synthesized highly-pointed gold nanostars. These particles were chosen because of their high electrical conductivity and especially for the presence of nanosized sharp tips on their surface. These features generate an enhancement of the local electric field increasing the tunneling probability between the particles. Different figures of merit concerning the morphology of the fillers were evaluated and correlated with the corresponding functional response of the composite.

[1]  Candido Pirri,et al.  Synthesis and Characterization of Gold Nanostars as Filler of Tunneling Conductive Polymer Composites , 2012 .

[2]  Giancarlo Canavese,et al.  Comprehensive Characterization of Large Piezoresistive Variation of Ni-PDMS Composites , 2011 .

[3]  J. Glatz-Reichenbach,et al.  Conducting polymer composites , 1999 .

[4]  David Bloor,et al.  A metal–polymer composite with unusual properties , 2005 .

[5]  J. Glatz-Reichenbach,et al.  FEATURE ARTICLE Conducting Polymer Composites , 1999 .

[6]  S. Kulkarni,et al.  Giant piezoresistive response in zinc–polydimethylsiloxane composites under uniaxial pressure , 2008 .

[7]  C. Bignardi,et al.  Stretchable and conformable metal–polymer piezoresistive hybrid system , 2012 .

[8]  U. Valdrè,et al.  Microscopy and computational modelling to elucidate the enhancement factor for field electron emitters , 2001 .

[9]  Gábor Harsányi,et al.  Polymer films in sensor applications: A review of present uses and future possibilities , 2000 .

[10]  Cheng Luo,et al.  Reinforcement of PDMS masters using SU-8 truss structures , 2005 .

[11]  M. Shimojo,et al.  A tactile sensor sheet using pressure conductive rubber with electrical-wires stitched method , 2004, IEEE Sensors Journal.

[12]  Shoko Yoshikawa,et al.  Resistivities of conductive composites , 1992 .

[13]  Giovanni Ausanio,et al.  Giant resistivity change induced by strain in a composite of conducting particles in an elastomer matrix , 2006 .

[14]  Benjamin C. K. Tee,et al.  Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers. , 2010, Nature materials.

[15]  Y. Mai,et al.  Effects of particle size, particle/matrix interface adhesion and particle loading on mechanical properties of particulate–polymer composites , 2008 .