A multi-function amperometric microsensor for medical applications

The fabrication and characterization of a microelectronic-based sensor for amperometric measurement are introduced. This microsensor consists of an electrochemical cell, a current-to-voltage amplifier, and a voltage-controlled resistor. By using this voltage-controlled resistor as a feedback impedance, a linear conversion of the current-to-voltage amplifier can be achieved with a flexible dynamic range of the induced currents in various sensing applications. The proposed microsensor is implemented by using the UMC 0.5 μ CMOS technology with a die size of 1.0 mm×1.0 mm. This electrochemical cell is a two-electrode scheme and its enzyme area is 600 u×800 u to generate the induced current that is proportional to the concentration of the test material. Our amperometric microsensor can effectively perform the operation of amplification, and signal transformation from the practical example of glucose proposed microsensor is also presented.