All-organic microelectromechanical systems integrating electrostrictive nanocomposite for mechanical energy harvesting
Résumé
Recent advances in the field of microelectromechanical systems (MEMS) have generated great interest in the
substitution of inorganic microcantilevers by organic ones, due to their low cost, high flexibility and a simplified
fabrication by means of printing methods. Here, we present the integration of electrostrictive nanocomposites
into organic microcantilever resonators specifically designed for mechanical energy harvesting from ambient
vibrations. Strain sensitive nanocomposite materials composed of reduced graphene oxide (rGO) dispersed in
polydimethylsiloxane (PDMS) are integrated into all-organic MEMS by means of an innovative low-cost and
environment friendly process by combining printing techniques and xurography. Static tests of the electrostrictive
nanocomposite with 3.7 wt% rGO show good performances with variations of capacitance that exceeds
4% for strain values lower than 0.55% as the microcantilever is bent. The results in dynamic mode suggest that
the organic MEMS meet the requirements for vibration energy harvesting. With an applied sinusoidal acceleration
(amplitude 0.5 g, frequency 15 Hz) a power density of 6 μW/cm3 is achieved using a primitive circuit.