The liquid metal actuated ejector vacuum system: (a) Schematic of a typical ejector; (b) Schematic of the system; (c) CAD system drawing; (d) Real system of the assembled prototype; (e) Flow conditions of GaInSn alloy when the system is running. 

An ejector vacuum system using nontoxic room-temperature liquid metal as actuating fluid was fabricated and experimentally demonstrated. With physical merits of high density, fluidity, and ultralow vapor pressure, the liquid metal could serve as a high momentum density carrier fluid. The main performance parameters of the liquid metal actuated ejector were thus found to be significantly improved by orders superior as compared with that of water actuating system. Under oxidation protection, an ultimate vacuum pressure of 170 Pa was achieved and capacity of evacuating a 500 ml nitrogen reservoir from atmospheric pressure to 480 Pa within 96 s was obtained.

Applied Physics Letters, 2015