Embodiments are directed to devices configured to assist the flow of fluids in the body. The device comprises a covering for placing on the skin of a patient having protrusions which can contact the skin. The protrusions have a base proximal to a surface of the covering and an outer edge distal to the surface of the covering. Protrusions can be configured in an array, in a line perpendicular to desired fluid flow or in a spiral configuration, such that fluid flow is enhanced in the appropriate direction. The device can be configured as a prosthesis, an orthotic, a liner for a prosthesis or orthotic, or a wrap or covering that is positioned around a body part. The body part can be part of a lower limb, part of an upper limb, or other body part.