Pyrotechnic actuator:: a new generation of Si integrated actuator

Mechanical micro actuators on silicon is playing a major role in the development of microsystems. In this context, many structures have been performed on electrostatic, piezo electric or pneumatic actuators. However, limitations remain when energetic micro actuations have to be created. We propose in this paper, a new original type of actuation based on the force generated by the combustion of an explosive. It consists of a micromachined silicon microheater (3 mm x 3 mm x 0.3 mm) on which a thin film of propellant (2 mm x 2 mm x 0.2 mm) is deposited. Its functioning principle is based on a hot gas emitted by the auto combustion of the propellant when its temperature reaches 300 degrees C locally. In this paper, we present the results of a study (by modelling and experimental) of the ignition and combustion of a very small quantity of explosive onto a Si-micromachined microheater. We conclude by presenting two examples of applications showing the promising interest of this energetic actuator: the first application is the biomedical field. The second one, today is used for microspace craft attitude control. (C) 1999 Elsevier Science S.A. All rights reserved.