Recent developments in making glass shells from M-doped glow discharge polymer (GDP) deposited by plasma polymerization (where M = Si or Ti) have significantly expanded the diameter and wall thickness obtainable by this process. Further, the wall uniformity of glass shells made by this process are generally superior to those made by the traditional drop-tower approach. We have also been able to pressurize a glass shell with Ar by taking advantage of the permeability properties of the glass before it is converted to full density where it becomes essentially impermeable to most gases.
