Impedimetric fiber-based sensors for wound monitoring

Inhalt:
To cover the high demands for an integrated in vivo wound monitoring concept, reliable sensor solutions have been under investigation for the past ten years. In this approach a sensor solution produced by textile machines is presented. The textile fabrication offers a cost-efficient opportunity to produce yard goods of sensors. The fiber-sensor integrates biocompatible electrodes separated by the functional material chitosan. The biopolymer is pH-dependent and changes its swelling state with the pH. The analysis of a thin chitosan layer by impedance spectroscopy is presented. It reveals a pH-dependent increase of the impedance of 7% at 120 Hz. The reaction is relatively slow and lasts many hours. The fiber setup with thermally cross-linked chitosan achieves even more impedance changes with over 50% signal increase at 450 kHz. However, stability of the sensor is still limited and needs to be improved.