Smart Hydrogel Shaft Sealing System

Midé proposes to use its knowledge of hydrogels to develop a bulkhead shaft sealing device. The proposed system will incorporate hydrogel polymer embedded in an open cell foam. This polymer will be in a powder form until in the presence of seawater (i.e. in the case of a damaged bulkhead shaft seal). The influx of seawater will cause the hydrogels to become superabsorbent, and they will swell to many times their volume, blocking the flow of seawater by the damaged seal.The system is designed to allow a small margin of clearance between the foam and the shaft before it is activated, so the hydrogel sealing system can be pre-positioned before a leak occurs. When the foam-hydrogel composition swells, contact forces against the shaft will be small, and the foam material that will contact the shaft is designed to be low-friction, enabling continued use of the shaft even when seals are damaged. The hydogels will be designed to be selective, so only seawater will activate it. Other fluids the system might come in contact with (hydraulic oil, etc.) will not cause a false activation of the superabsorbency of the hydrogel.