Biodegradable Electrode patch made of Graphene/PHA for ECG detecting Applications

A biomedical electrode patch for detecting an electrocardiogram signal which is provoked by electrical activity through the heart has been investigated. The electrode patch was made of chemical derived graphene as an electrically conductive layer and polyhydroxyalkanoate (PHA) as a flexible substrate. This gra-phene/PHA patch has been promised to be completely biocompatible and biodegradable by microbes in terrestrial environments. According to the fabrication of the electrode patch, graphene was synthesized using Hummers' method and reduction with hydrazine hydrate. The PHA membrane, an aliphatic polyester bioplastic, was accumulated by Ralstonia eutropha and then was casted using electrospinning technique to serve nanofiber scaffold for an abundance of graphene to be addressed. The graphene/PHA electrodes were interfaced to 3-lead electrocardiogram (ECG) sensor and amplifier modules controlling by computing microcontroller. Real-time in vitro monitoring of the simulated ECG signals were observed, including normal condition at 60 BPM and abnormal heart rhythms, through the interfaces of graphene/PHA electrodes. The signals have been shown obviously and no degradation over time, however, the signal attenuation might increase due to in vivo measurement of human skin-electrode impedance.