AbstractMapping the functional response of the somatosensory cortex is useful both for characterizing normal brain activity and for determining the functional integrity of damaged cortex compromised by stroke or other neurological insults. A variety of stimulators have been used to produce somatosensory cortex activation in functional brain imaging, including brushes and swabs operated manually, pneumatically and mechanically powered mechanical vibrators, air puffs, and vibrating ceramic piezoelectric wafers and benders. A closed‐system, pneumatically driven rubber diaphragm is reported that overcomes many of the limitations of existing vibrotactile devices and produces robust sensory cortex activation in an fMRI experiment. Magn Reson Med 51:640–643, 2004. © 2004 Wiley‐Liss, Inc.