Why CMOS-integrated transducers? A review

In many applications up to millions of sensors or actuators have to be interconnected to each other and/or to the outside world, making the monolithic integration of circuitry mandatory. This monolithic integration is also pursued for mass-produced transducers because of economical reasons. CMOS-integrated transducers are thus found in imaging transducers arrays and mass-produced 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 selected work in the imaging and biochemical field is highlighted. Concerning imaging transducer arrays an overview is given of visible and IR imagers, displays and of inkjet printheads. Concerning the new field of biochemical sensor arrays, two examples are described: a blood-gas sensor and an array of interdigitated electrodes. Finally an overview of the possible technological approaches regarding integrated processing of transducers is presented.