Development of MEMS microsensors, aiming at the application in the study of muscle fatigue in vivo

Abstract

Many studies have been conducted in order to better understand the role of the pH in muscle fatigue. However, measuring in vivo pH concentration, in the muscular environment during anaerobic exercise, cannot be conducted through regular methods. Thus, in this work, we design and fabricate a siliconbased implantable microelectrode array (MEA) utilizing microelectronics and MEMS techniques. The probe consists of a microneedle with three pairs of electrodes, each containing one Ag-AgCl reference electrode and one Au-IrOx working electrode. The Au and Au/IrOx electrodes were tested in a potassium ferricyanide solution and, in order to verify the device sensitivity to pH, open circuit potential (OCP) measurements were carried out in 0.1 mol L-1 phosphate buffer solution (PBS) with different pH values. The results show a linear response to the solution pH in the studied range, proving that the probe is a promising sensor.