The invention relates to analyte monitoring/drug delivery device. The invention is suited for monitoring various blood constituents such as glucose. The device has a housing that at least partially encloses a plurality of microneedles disposed on a carrier and an electronics portion. Each microneedle is in fluid communication with a corresponding microchannel. Each microneedle is individually addressable. That is, each microneedle can be extended and retracted individually via an actuator. The invention can optionally provide for calibration without intervention of the user and can also provide for semi-continuous monitoring for day and night time. The invention can provide up to four, or more, weeks of operation. The invention can provide for a device that is relatively small in size, and therefore unobtrusive. The invention can also provide for device with remote control and interactive electronics. The invention may be also used for the delivery of various pharmaceutical agents.