Abstract: Systems, valves and methods for controlling fluid flow using the systems and the valves for applications involving the control of micro flow of fluids, such as, for example, spacecraft rocket thrusters, oil well production, medical/biological apparatus, industrial apparatus is disclosed. The valves used in the systems and in the methods include a housing having a cavity and an inlet and an outlet. A seat is positioned in the housing and connected to both the inlet and the outlet. A poppet member is positioned in the cavity relative to the seat for controlling fluid flow from the inlet to the outlet. A magnetostrictive member is positioned in the cavity and connected to the poppet member. Electromagnetic excitation means are positioned in the cavity relative to the magnetostrictive member such that current applied to the electromagnetic excitation means controls the position of the poppet relative to the seat.

Abstract: A valve construction relies upon solenoid-driven axial elongation of an annular magnetostrictive core element for opening displacement of an elongate poppet-valve member that is carried within the annulus of the core element. A first stiffly compliant preload independently urges the poppet-valve member into its seated position of lock-up at valve closure, and a second stiffly compliant preload independently prestresses the annular magnetostrictive core element into a fixed referencing abutment with valve-body structure. The currently preferred material of the core is Terfenol-D, which offers a strong elongation response to inductively coupled excitation. The elongation response is sufficient to serve the purposes of (1) closing a pretravel clearance prior to a flange engagement with the poppet-valve member and (2) also, via the flange engagement, displacing the poppet-valve member out of its normal valve-closing engagement with the valve seat.