UNISA folded pendulum technological platform for the implementation of mechanical inertial broadband low-frequency high-sensitivity sensors for ground, marine and space applications

The UNISA Folded Pendulum technological platform is very promising for the implementation of high sensitivity large broadband miniaturized mechanical seismometers and accelerometers in different materials. In fact, the symmetry of its mechanical architecture allows to take full advantage of one of the most relevant properties of the folded pendulum, that is the scalability. This property is very useful for the design of folded pendulums of small size and weight, provided with a suitable combination of physical and geometrical parameters. Using a lagrangian simplified model of folded pendulum, we present and discuss this idea, showing different possible approaches that may lead to the miniaturization of a folded pendulum. Finally, we present a prototype of a miniaturized inertial sensor, characterized by a resonance frequency of 0.5 Hz, a measurement band of 1 mHz divided by 1 kHz, a weight of 40 g and a size of 5 cmx 5 cmx 1. 8 cm, discussing its characteristics and limitations, in connection with scientific ground, marine and space applications.