The field of DNA microarrays or DNA chips can potentially revolutionize the acquisition and analysis of genetic information. In these devices, DNA hybridization may occur in a massively parallel manner with different single-strand DNA capture probes immobilized at specific sites on a microarray. This talk will be divided into two parts: (1) a general overview of the different technologies presently being used in fabricating DNA chips and (2) an introduction to the work being done at INESC MN on the addressing of DNA molecules using electric field pulse and their detection with an integrated photodetector.