Polyaniline-coated nylon lycra fabrics for strain sensor and electromagnetic interference shielding applications

In this article, a conductive polyaniline-coated nylon lycra fabric has been characterized for electromagnetic interference (EMI) shielding and strain sensor application. The conductive fabric is fabricated by in-situ polymerization of polyaniline on the nylon lycra fabric at low temperature. Characterization has been carried out using scanning electron microscopy and differential scanning calorimetry. The sensitivity of the developed fabric sensor is characterized using Zwick tensile tester. EMI shielding efficiency (SE) of the developed fabrics is carried out as per ASTM D4935 standard. The stability of the developed sensor is characterized with respect to temperature and humidity using Programmable Environmental Test Chamber. The measurement of the conductivity change with strain shows that the fabrics so prepared exhibits high strain sensitivity, while its good stability is indicated by a small loss of conductivity after the thermal and humidity ageing tests and supported by the slight change in conductivity over storage of 90 days. The sensor measures flexion angle of elbow up to 120° angle. The electromagnetic shielding tests show that the developed conductive fabric has the EMI SE of 26 dB in the frequency range of 8–12 GHz.