There is provided a medical device (1) comprising a skin attachment surface (3) and an evaporation layer (9), and at least one hollow microneedle (4) extending from the skin attachment surface (3), the device (1) further comprising a flow channel (6), an analysis unit (8)for analysing a body fluid, and an evaporation layer (9), where the flow channel (6) is arranged to transport fluid from the microneedle (4) to the analysis unit (8) and from the analysis unit (8) to the evaporation layer (9), such that the flow channel (6) can release fluid into the evaporation layer (9).
