Osmotic engine.

Above: Osmotic engine diagram. 

“Osmotic power plants harness the same principle as osmosis: water moving from a less concentrated solution to a more concentrated one across a semipermeable membrane. At Fukuoka, electricity is produced from the salinity gradient between two streams placed on either side of a semipermeable membrane. 

On one side, there is concentrated seawater created by extracting fresh water; on the other, treated water from a sewage treatment facility. The membrane allows water to pass but blocks impurities. As water naturally moves toward the saltier side, pressure builds and is used to spin a turbine, which then drives a generator.

The osmotic engine can give.  A big advance in nanotechnology. And that system can also revolutionize energy production, if full-scale osmotic systems can be produced someday. The osmotic engine's basis is in osmosis. When there is a semi-permeable membrane between two liquids. Another is a strong salt mixture, and the other is a weaker mixture. Water travels from a weak concentration. To the strong concentration. The flow continues until those concentrations have the same salt content. “ (Interesting Engineering, Inside Asia’s first osmotic power plant: How Japan turns saltwater into electricity )

There is a possibility of using osmosis as a power source. Those systems are tested in Japan and Denmark.

The semi-permeable membrane can have nano-sized propellers in the holes. The water flows between those concentrations. And puts those propellers into motion. Nano-propellers make nano-sized generators rotate. The problem is that. It is needed. A lot of those nano-sized systems. This makes those systems hard to make.

In some other versions. Osmosis drives liquid into the other side of the piston. There, that membrane makes a “window”. This allows the osmotic reaction, which raises the piston. 

On a large scale. There are plans. To create closed-cycle osmotic engines. The idea is that the osmotic engine makes water flow. Through that membrane. The system takes energy from that movement. Then the system can use the capillary effect. To flow that liquid up. Then the system drops liquid through another membrane. This separates salt from water. Then that separated salt will be driven to the chamber where there is a stronger concentration. 

The osmosis engine is one of the things. That can be the power source of the future. The system can give energy to things. Like small-scale underwater systems. The system must only filter salt from the water flow. Then it drives that distilled water under the membrane. And then the osmotic force pulls. That distilled water passes through the membrane to the salt water. There is also a possibility to connect. The small-sized underwater robot movement. 

To this system. The system can drive distilled water behind the osmotic, or semi-permeable membrane. Then that water travels. To a stronger salt concentration. This forms the pushing effect. This kind of system. There is a membrane that removes salt from water. Making an osmotic pressure. Pushing those nano-robots forward can revolutionize the movement. The membrane can make the cleaning process by moving back and forth. Then that weaker salt concentration travels to the nanomachines' osmotic membrane. These kinds of systems can enable nanomachines to move very well.  The osmotic systems can be used. In small robot submarines. That should move in the blood vessels. 

https://interestingengineering.com/energy/asias-first-osmotic-power-plant

https://www.kt.dtu.dk/newsarchive/2023/02/the-power-of-osmosis

https://www.mdpi.com/2310-2861/7/4/232

https://patents.google.com/patent/US20100024423A1/

https://www.sciencedirect.com/science/article/abs/pii/B9780128236901000101

https://en.wikipedia.org/wiki/Osmotic_power