FINGERTIP CONFORMING FLUID EXPRESSION CAP

A bodily fluid sampling device includes an incision forming device to form an incision in a finger and an expression cap. The expression cap has an opening through which the incision forming device forms an incision and an expression surface to express fluid from the incision. The expression surface has at least two opposing compression surfaces with a negative sigmoidal shape to enhance expression of body fluid from the incision. The expression cap defines a relief notch between the compression surfaces, and the relief notch is sized to receive the finger, or some other body part, to permit the compression surfaces to first contact the finger when the expression surface is pressed against the finger.