Electrochemical Oxygen Microsensors

Recent developments in the field of silicon microfabrication techniques offer advanced technologies to improve the sensing part of macroscopic electrochemical gas sensors by means of a miniature chip. The miniaturized, low-size and low-cost devices are changing the market: the existing market is reshuffled and new applications in biotechnologies and environmental control are opened. We have realized oxygen microsensors providing a different packaging able to work in liquid or gaseous phases. These oxygen microsensors are based on the basic electrochemical principle of the Hersch cell. The device is made of two micromachined silicon wafers: the lower wafer supports the sensitive part (electrodes, cavity filled with electrolyte) and the upper one supports the membrane. According to applications, microsensors are packaged and conditioned differently. Laboratory tests are promising.