Electrical and piezoresistive properties of multi-walled carbon nanotube/polymer composite films aligned by an electric field

Drastic modification of the piezoresistive behavior of polymer nanocomposites by using conductive polymer coatings

“…In the CNT/PC samples, regardless of the MWCNT concentration, k was larger than the pure geometrically induced value of 1.76 (marked as a dashed line on Figure 4(a)), whereas it was less than this value in the samples with PEDOT/PSS-coated MWCNTs. For CNT/PC samples, the k values found are consistent with those in the literature [4,6,8,10,14]. This is the first evidence that the piezoresistive behavior is largely amplified by the strain dependency on the nanocomposite's electrical volume resistivity (the term dρ ρ·ε in Equation 4).…”

“…Strong, non-linear piezoresistive behavior, like that exhibited by CNT/PC samples, has been found experimentally [7,6,10] and theoretically [14,15] in materials with easily disrupted percolating network of conductive fillers embedded in a highly resistive matrix. Typically, the tunneling resistance increases exponentially with respect to separation between fillers.…”

“…Typically, the tunneling resistance increases exponentially with respect to separation between fillers. Some of the known microstructural features that promote strong piezoresistive behavior (and usually low electrical conductivity) are the low concentration of conductive fillers [6], the poor dispersion of fillers and nanotube agglomeration [14], the alignment of fillers in the direction of the deformation [10], and the use of fillers with small aspect ratios, such as carbon black particles [6]. We attribute the strong piezoresistive effect of CNT/PC samples to the random distribution of MWCNTs.…”

“…Indeed, several limitations have been observed. For example, the nanocomposites described in [6] and [10] exhibit non-linear piezoresistive behavior, strong deviations between elastic and plastic regimes and sensitivity to inelastic deformation and material degradation.…”

Elektronik Tekstillere Yönelik Akıllı Kumaş Sensörleri

“…MWCNT'ler (çok duvarlı karbon nanotüp) de film formunda iken piezorezistif özelliklere sahip olabilmektedirler [68]. Karbon siyahı partiküllerde olduğu gibi, karbon nanotüplerin piezorezistif duyarlılığı, artan dolgu konsantrasyonuyla azalmaktadır [69].…”