Temperature-compensated force/pressure sensor based on multi-walled carbon nanotube epoxy composites

Sensors (Basel). 2015 May 12;15(5):11133-50. doi: 10.3390/s150511133.


In this study, we propose a multi-walled carbon nanotube epoxy composite sensor for force and pressure sensing in the range of 50 N-2 kN. A manufacturing procedure, including material preparation and deposition techniques, is proposed. The electrode dimensions and the layer thickness were optimized by the finite element method. Temperature compensation is realized by four nanocomposites elements, where only two elements are exposed to the measurand. In order to investigate the influence of the filler contents, samples with different compositions were prepared and investigated. Additionally, the specimens are characterized by cyclical and stepped force/pressure loads or at defined temperatures. The results show that the choice of the filler content should meet a compromise between sensitivity, temperature influence and noise behavior. At constant temperature, a force of at least 50N can be resolved. The measurement error due to the temperature influence is 150N in a temperature range of -20°C-50°C.

Keywords: carbon nanotubes; composite; electrical response; epoxy; force sensor; multi-walled carbon nanotubes; pressure sensor; temperature compensation; thermal response.