07/24/2026
Syringe Mechanism💉
A syringe works by creating pressure differences inside its barrel.
I pulled this plunger backwards, now the volume of barrel is increased. we know that volume is inversely proportional to pressure, so when barrel's volume increased, the pressure inside the barrel decreased.. but the liquid, which is outside of the barrel has still the same pressure as before.
it means, now the barrel has low pressure and liquid outside the barrel has high pressure.
fluids naturally move from higher pressure to lower pressure, so the liquid is pushed into the syringe through the tip.