Micro-thrusters for satellites

How it works
Micro-thrusters can use different technologies, but the technology of interest here is the so-called “cold gas micro-thruster”. In this approach, the thrusters generate a very small and controlled force (<500µN) by expelling a jet of gas, typically Nitrogen, stored in a high-pressure tank. This requires both an accurate control of the pressure of the propellant in the circuit and a fast and precise “dispensing”. Piezo actuators integrated into valves can ensure both functions. For redundancy, the micro-thrusters are fitted with several piezo actuators. The movement of the piezo actuators ensures a fast and precise control of the flow during operation.

Which piezo elements can be used for micro-thrusters for satellites?
On the low-pressure side, the piezo elements integrated in micro-thrusters are selected for their low power requirements, reduced size and mass, high stroke, low force. For this application, a multilayer bending actuator is preferred, providing fast and precise motion in a small package.