Complex sentence: One design achieves this by creating a plunger that inserts itself into the syringe neck to expel as much fluid as possible from the syringe body, thus reducing the amount of space available within the neck.
Split into simpler sentences: One design achieves this by creating a plunger that inserts itself into the syringe neck to expel as much fluid as possible from the syringe body. Thus reducing the amount of space available within the neck.