摘要 |
<p>A device (1) for causing the displacement of a piston (36) or diaphragm (4) comprising an enclosure containing unsaturated super-absorbent material (38) and including a piston or diaphragm; and a fluid inlet into the enclosure adapted to allow fluid into the enclosure and restrain the super-absorbent material form escaping from the enclosure; such that as fluid is allowed into the enclosure, it is absorbed by the super-absorbent material which swells against the piston (36) or diaphragm (4), causing displacement thereof. The piston (36) or diaphragm (4) may form at least one wall of the enclosure. Alternatively diaphragm may be a membrane of elastomeric material within the enclosure. The invention may be used in a drug delivery system, a air freshener, or a lavatory cleaner.</p> |