While most of us (including this writer) will cringe at the mere mention of syringes and their uses in the medical field to give people shots, they do have other uses. The way they work has inspired several different machines and you probably use the mechanics of a syringe every single day. A high pressure syringe works by using pressure and consists of a plunger inside of a tube.
By pulling or pushing the plunger, air and liquid are either drawn in or forced out by suction. The increase and decrease in pressures are what pull liquid in or force it out, allowing for precise amounts to be injected in precise areas. Other items, such as eyedroppers, use the same principle. Syringes are commonly used in the medical field to give medications or perform delicate lab work, but the principle of pressure works in other ways.
For example, a water gun uses a syringe in its barrel. To load most water guns, the gun is submerged underwater and water is allowed to enter it. Pressure keeps most of the water inside, and when the trigger is pulled it’s like pushing down on the button of a syringe. Then the water fires out to hit your target.
They are also used during cooking, where people inject baked goods or meats with a syringe full of juices or fillings. Then they fill up the object with the contents of the syringe, ensuring that the food is filled without having to cut it open. Even pumps, whether for a pool or for oil, operate on syringe principles.
The handle is pumped, and pressure forces the water/oil out of the ground and into the outside where it can serve its purpose. Syringes might get a bad name because of their medical connotations, but their principles serve the world in dozens of ways.