If this process for making aerogel is right, then you could just mix in whatever ratio of liquid helium/hydrogen with the liquid carbon dioxide when you flush out the alcohol. You could make a flying carpet this way!<br /><br /><font color="yellow">From scratch, Hunt's aerogel process begins with the mixing of TEOS and water. To allow these two immiscible fluids to loosen up and mix, alcohol is added. The water breaks apart the TEOS, attacking the silicon bonds, and creating an intermediate ester that condenses into pure silica particles. With the assist of a catalyst, ammonium fluoride, and a solution of ammonium hydroxide to control the pH, the silica particles grow and link, forming an alcogel. A clear gel, the alcogel is sufficiently strong so that when a bottle is half filled with it and turned upside down, it will not flow. <br /><br />The gel is then inserted into a pressure vessel where liquid carbon dioxide flushes out and replaces the alcohol in the gel, reducing potential fire risks in the process. Pressure is increased, the carbon dioxide becomes supercritical, and as it is slowly vented, the alcogel dries into an aerogel. </font><br /><br />