Self-Assembled Polymer Thin Films Towards Nanoarchitectonics for Respiration Monitoring

Manipulation of ionic transport in the self-assembled polymer thin films using nanoarchitectonics approach can open the door for the development of novel electronic devices with ultrafast operation and low-power consumption. Here, we demonstrate a highly sensitive and ultrafast responsive flexible humidity sensor for human respiration monitoring. Humidity sensing behavior of the polymerbased planar devices, in which a polyethylene oxide-phosphotungstic acid (PEO-PWA) thin film is placed between an opposing inert electrodes, have been investigated by optimizing the device configuration and PWA salt concentration in the PEO matrix. The ultrafast response (~50 ms) and recovery (~52 ms) of the humidity sensor enabled us to study the real-time human respiration monitoring. Using morphological analysis, it is proposed that the ultrafast response-recovery time for this sensor is ascribed to their self-assembled lamellar-like structures of the PEO-PWA matrix polymer, which provides long-range continuous proton transport path in the polymer interface.