A strip-like microneedle device is provided that includes an array of hollow microneedles, a diaphragm pump to extract interstitial fluid from skin, and a sensor that detects the concentration of the fluid. The microneedle device can be interfaced to an external sensor to produce a reading, or can be self-contained. One version uses an attachable/detachable microneedle array as a single-use, disposable unit. The device is portable, and is used by placing one finger on the microneedle array, and actuating the diaphragm pump with another finger, thereby obtaining the fluid sample. Solid coated or transparent microneedles could instead be used as an in-situ sensor, with either electrodes or an optical sensor.