A substance delivery device includes an elongated tubular body having opposing proximal and distal ends, and a diaphragm that is in slideable sealing engagement with an inside wall of the tubular body. The diaphragm is movable in opposite first and second directions within the tubular body. A substance is contained within the tubular body between the diaphragm and the tubular body distal end, and a slave fluid is contained within the tubular body between the diaphragm and the tubular body proximal end. When pressure is exerted on the slave fluid, the slave fluid causes the diaphragm to move and eject the substance through the tubular body distal end.