A medical device, such as a vascular filter, composed of: a reinforced membrane unit composed of: a thin filter membrane; and fibers of reinforcement material embedded in the membrane to strengthen the filter and securely attach the fibers to the membrane.A method of fabricating the filter by the steps of: providing a mold that can be melted, dissolved, or deformed without damaging membrane material; covering the mold with an intermediate material that is easily separated from the membrane material; covering the intermediate material with the membrane material; placing the fibers in contact with the membrane material that covers the intermediate material; covering the fibers with additional membrane material to form the membrane with embedded fibers; removing the mold by melting, dissolving, or deforming the mold; and removing the intermediate material from the membrane.