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 polymer-based 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 (similar to 50 ms) and recovery (similar to 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.