Titanium dioxide based bioelectric sensor for the acquisition of electrocardiogram signals

Abstract

We report the development of dry sensors that do not require the use of gel or preparation of skin for Electrocardiogram (ECG) signal detection. Bioelectric sensors are transducers that convert ionic currents within the body into electron currents, which can be collected and processed to monitor the activities of the human body. Biopotentials of the human body are usually measured with conventional, Ag/AgCl sensors or electrodes. These sensors provide good quality signals but suffer from signal degradation after a short period of usage. Ag/AgCl sensors also require the skin to be prepared before measurement and also need frequent replacement of the conductive gel for prolonged use of the sensors. To overcome these limitations, dry bioelectric sensors have been developed which do not require the usage of conducting gels. The dry sensors have been fabricated using Titanium dioxide (TiO2) nanoparticles as base and the properties of the sensors have been tuned by doping it with aluminum to achieve the required bioelectric potentials. Impedance measurements have been performed to understand the behavior of the sensors on unprepared skin. The sensors have been integrated with a signal acquisition system to record Electro Cardio Gram (ECG) signals. The signals achieved from the fabricated sensors were found to be on par with the signals obtained from the commercially available pre-gelled sensors.