Modelling and analysis of a combined electronic and micro-mechanical system

The modelling of micro-mechanical systems in combination with integrated electronic circuits is a complex task demanding a knowledge of mechanical and microelectronic design in combination with system-modelling expertise, especially in cases where new possibilities regarding system construction and its properties are taken into account. Such modelling is becoming increasingly important because of the rapid growth of so-called "smart sensor" applications based on micro-mechanical devices. Our task was to create a reliable model of a micro-mechanical acceleration sensor that uses an extremely small and easy-to-produce mechanical system. The suspended mass and the output signal of this sensor are one order of magnitude smaller than existing systems. The described model was used for the further development of the mechanical and electrical parts of the system. The modelling inputs were the measurement data of the prototype devices, comprising the static characteristics of the device and the system responses to step-function excitation. Together with known physical properties and basic theoretical equations these data enabled us to create the described model, which showed good agreement with the measurement results. Modeliranje mikro-mehanskih sistemov, ki delujejo v kombinaciji z integriranimi elektronskimi vezji, je dokaj zahtevna naloga, ki zahteva poznavanje načrtovanja sistemov z obeh področij v kombinaciji z matematičnim modeliranjem, kar je se posebej pomembno, kadar zelimo proučiti nove možnosti delovanja obravnavanega procesa in njegove lastnosti. Tovrstno modeliranje postaja vse pomembnejše, saj vse hitreje narasča uporaba tako imenovanih "pametnih senzorjev", ki temeljijo na mikro-mehanskih sistemih. Naša naloga je bila načrtati zanesljiv model mikro elektro-mehanskega senzorja pospeška, ki uporablja ekstremno majhen mehanski sistem, katerega proizvodnja je nezahtevna. Vpeta masa in izhodni signal tega senzorja sta za velikostni razred manjša od obstoječih sistemov. Opisani model smo nadalje uporabili pri razvoju mehaničnega in električnih delov sistema. Pri razvoju modela smo uporabili tudi meritve prototipnih naprav, s pomočjo katerih smo preverjali statične lastnosti, pri odzivu na stopničasta testna vzbujanja pa tudi dinamične. Ob upostevanju poznanih fizikalnih zakonitosti in ravnotežnih razmerij smo razvili predstavljeni model, ki se zelo dobro ujema z izvedenimi meritvami.