Why CMOS-integrated transducers? A review

In many applications up to millions of sensors or actuators have to be inte rconnected to each other and/or to the outside world, making the monolithic integration of circuitry mandatory. This monolithic integration is also pu rsued for mass-produced transducers because of economical reasons. CMOS-int egrated transducers are thus found in imaging transducers arrays and mass-p roduced physical sensors. In addition, integrated biochemical sensor arrays can be CMOS-integrated. In this article first a general overview of the field is given and then sel ected work in the imaging and biochemical field is highlighted. Concerning imaging transducer arrays an overview is given of visible and IR imagers, d isplays and of inkjet printheads. Concerning the new field of biochemical s ensor arrays, two examples are described: a blood-gas sensor and an array o f interdigitated electrodes. Finally an overview of the possible technologi cal approaches regarding integrated processing of transducers is presented.