To make a liquid come out when you inject it, you would need to create a system that generates pressure to push the liquid out. Here are a few approaches you can consider:
Syringe with Plunger: Use a syringe with a plunger mechanism. When you pull the plunger back, it creates a vacuum inside the syringe, causing the liquid to be drawn into the syringe. Then, when you push the plunger forward, it applies pressure on the liquid, forcing it out through the needle or nozzle.
Pumping Mechanism: Utilize a pumping mechanism such as a peristaltic pump or a piston pump. These devices use mechanical or motorized actions to create pressure that pushes the liquid out. By controlling the pump's action, you can inject the liquid in a controlled manner.
Compressed Air or Gas: Connect a source of compressed air or gas to a container or vessel holding the liquid. By pressurizing the air or gas, it creates pressure on the liquid, causing it to be expelled when a valve or outlet is opened. This method is commonly used in certain types of spray bottles or pressurized dispensing systems.
Gravity and Height Differential: If the liquid you want to inject is stored at a higher level than the destination, you can rely on gravity to create the necessary pressure. By opening a valve or using a siphon system, the liquid will flow down due to gravity, generating the desired flow.
Remember to consider the specific requirements of your application, such as the volume and viscosity of the liquid, the desired flow rate, and any safety considerations. It may be helpful to consult with an expert in fluid dynamics or engineering to design an appropriate system based on your specific needs.