The role of thermal treatments in the transition from insulating to semiconducting PANI Films: For respiration monitoring applications

Abstract

EDA (Ethylenediamine)-doped PANI films were easily prepared by the spin coating method. The films are treated at different temperatures and times, 100 ℃/4h, 150oC/1min, 150 ℃/30min, and 150 ℃ / 1h. Several methods including FT-IR, TEM, and XRD described the characterizations of PANI films. The samples' conductivity change during human respiration was investigated. A respiration frequency of 0.3, 0.29, 0.35, and 0.354 Hz was obtained via 100 ℃ / 4h, 150 ℃ / 1 min, 150 ℃ / 30 min and 150 ℃ / 1h, respectively for adult respiration at rest, which agreed well with the previously reported values. The 100 ℃ / 4h sample distinguished every exhaling cycle and showed a clear baseline during the continuous respiration monitoring. However, in the case of a high annealing temperature and time, the samples distinguished every cycle but without a defined baseline. This demonstrates the ability of the 100 ℃ / 4h sample to determine the calm state respiration frequency of humans with a defined baseline.