A system for a patch-like, self-contained substance infusion device (100) which provides one or more substantially hidden patient needles (141) which can be placed in fluid communication with a fluid reservoir assembly that includes a rigid bladder portion (151) used in conjunction with a flexibe membrane. The device (100) can be attached to a skin surface via an adhesive contact surface. The reservoir has a body opening providing fluid communication from the reservoir to the lumen of the injection needle. A valve is disposed within the body opening which moves longitudinaly with respect to the axis of the body opening.
