Abstract: A medical device for the delivery of fluids into or through the wall of a biological space or conduit is described. The medical device comprises one or more actuators, which may exist in a constrained configuration which is substantially parallel to the longitudinal axis of the device or an unconstrained configuration in which at least a portion of the one or more actuators is oriented substantially non-parallel to the longitudinal axis of the device. The device further comprises tissue penetrators, which may be attached to the actuators or contained within the actuators. Upon positioning of the device at the target treatment site within a biological space or conduit, the operator may release the actuators from their constrained position, allowing the actuators to adopt their unconstrained position and make contact with an adjacent wall of a biological space or conduit.