A highly-deformable composite composed of an entangled network of electrically-conductive carbon-nanotubes embedded in elastic polyurethane

The electrical resistance change of a highly extensible composite consisting of a network of entangled multi-wall carbon nanotubes in a thermoplastic polyurethane elastomer is tested. The composite is prepared by taking a non-woven polyurethane filter membrane, enmeshing it with carbon nanotubes and melding them together. Testing has shown that the material can be elongated as much as 400% during which the resistance is increased more than 270 times. It indicates favorable properties of the composite for its use as a highly-deformation strain sensing element, a strain-electric signal transducer, electromagnetic field shielding and protection against lightning. As an example of its use as a strain sensor, human knee flexion and knee cyclic movement has been monitored. This may be of use in orthopedics and rehabilitation. (C) 2012 Elsevier Ltd. All rights reserved.