Biomimetic sealing system for streamflow generation

Renewable energy research has been promoted to slow down climate change and maintain economic growth. Streamflow is valued as a source of energy, and environmentally friendly and low-friction sealing system that employs biomimetic technologies is proposed for its utilization. A dynamo-electric generator and ancillary systems with waterproof construction are installed under water. Lip seals with a rotating shaft function to prevent the ingress of water from the outside and excellent frictional properties with various rotation speeds are required to improve the power generation efficiency with constantly changing water flow. The sealing system was successfully developed using a hydrated material (polyvinyl formal; PVF) that mimics articular cartilage in a natural synovial joint. Polyethylene glycol (PEG) dissolved in distilled water, which is a non-Newtonian fluid, was used as a lubricant. These materials have low toxicity and low environmental impact. The biomimetic sealing system exhibits excellent frictional properties with extremely low ingress of water.