Large deformation balloon micro-actuator based on pyrotechnics on chip

This communication presents the modeling and the first demonstration of very large deformation balloon actuators based on pyrotechnics on chip. The gas and pressure generated by the combustion of a solid propellant stored in a micromachined cavity lead to the large deformation of the elastic membrane closing the cavity, forming a balloon with a radius of few millimeters. By combining the experimental data obtained on the mechanical properties of the elastic membrane and volume of gas generated per unit of mass of the propellant, design rules were defined for the realization of balloon actuators based on pyrotechnics. The dimensions of the system linked to the volume of propellant allow tuning the amplitude of the deformation of the membrane obtained during its combustion. The pyrotechnic balloon actuator fabricated is capable of large out of plane deflection (up to 6 mm) in few milliseconds. The work performed has generated a strong base for the further development of this actuating technology, especially in space exploration where the use of a combustible in a solid form brings many advantages.