A composite wound dressing apparatus promotes healing of a wound via the use of a micropump system. The micropump system includes a micropump that applies a subatmospheric pressure to the wound to effectively draw wound fluid or exudate away from the wound bed, or deliver fluids to the wound bed, without the need for a cumbersome external pressure (e.g. vacuum) source. Hence, the wound dressing and micropump system is portable which allows the patient mobility that is unavailable when an external vacuum source is used.