Electric Micro-Propulsion in Low Temperature Co-Fired Ceramics

A miniature electrostatic thruster has been developed in Low Temperature Co-Fired Ceramics (LTCC) at Boise State University. The thruster is composed of an inductively coupled plasma (ICP) antenna, plasma containment cylinder, and ion extraction grids for propulsion. LTCC is a good candidate for electric micro-propulsion because of its resistance to plasma degradation and three dimensional capabilities. LTCC can be fabricated into planar structures or rolled geometries, both capable of fluidic and electrical paths. The miniature ICP thruster developed at Boise State University encompasses all the beneficial attributes of LTCC. A planar ICP antenna with fluidic channels and electrical pathways is used as the plasma source of the thruster. The antenna has been characterized and can ignite a plasma at 3 W to 50 W while sustaining the plasma down to .1 W. The pressure ranges for these tests were from 50 mTorr to 1.75 Torr. A rolled LTCC cylinder has been made for plasma containment and integrated with extraction grids. The two ion extraction grids are embedded into the cylinder and are electrically connected through to the bottom of the antenna. Characterization of the thruster will determine the geometry of the plasma as well as the thrust measurement. Other research institutes have witnessed the advantages of using LTCC for this application. In conjunction with another research group, a pulse inductive thruster (PIT) has been developed in LTCC. The PIT is a planar device with multiple ICP antennas as the plasma source and embedded with conductive coils for ion propulsion. Electric propulsion, plasma transistors, and plasma displays are only a few of the many current research developments that are taking advantage of LTCC’s favorable attributes for plasma applications