Fabrication Technique in Surface Sintering Assisted Graphite Nanoplatelets Coated Thin Film Polymer Nanocomposites as Resistance Strain Gages

Resistance strain gages have wide applications in development of electronic devices, robotic technologies and force and torque loadcells. However, one main issue besides their rather high cost is their low gage factor and quite low range of linearity in high strain applications that results in challenges in design and development of load cells when calibration is of high importance in accurate measurement of loads. Moreover, fabrication techniques so far are so sophisticated and time-consuming involveing several stages. This report focuses on introduction of a technique in fabrication of ultra-flexible electrically conductive polymer nanocomposite sheets as resistance strain gages using film fabrication technology on the calendering rolling mixing machine. Soft polymeric thermoplastic polyolefines such as low-density polyethylene (LDPE) was used as the main substrate coated with graphite nano-platelets (GNPs) as electrically conductive nanomaterials. To decrease the percolation threshold, it was hypothesized that coating of the fillers is applied onto the polymeric sheets under heat and pressure on the roller mixing under high shear forces. The results suggested the feasibility of the technique used in fabrication electrically conductive thin sheets capable of maintaining their conductivity under intense bending. Moreover, it was indicated that the conductivity of the specimens was highly dependent upon the nano-reinforcements used. Initial results conformed the linear relationship between the sensors resistance and the length as expected. Further studies are suggested to be performed to estimate the gage factored of the fabricated sensor over a specific limit of applied load on a home-made single-cantilever load cell devise.

Keywords:

Calendering , strain gage , sensor , electrical conductivity , percolation threshold