Silicone-based elastic composites able to generate energy on micromechanical impulse

摘要

Elastic composites were prepared based on a polydimethylsiloxane-alpha,omega-diol (M-w = 139 000 g mol(-1)), different alpha,omega-bis(trimethylsiloxy) poly(methylcyanopropyl-methylhexyl-methylhydro) siloxanes as the polar group component and TEOS as a cross-linking agent and silica generator. The resulting materials consisted of polar-nonpolar interconnected networks as matrices which had 7.4 or 9.5 wt% in situ generated silica and contained up to 2.74 wt% CN groups. The films formed were tested for electromechanical response to a micromechanical impulse. It was found that their performance was proportional to their electromechanical sensitivity (beta = epsilon'/Y, where epsilon' is the dielectric permittivity and Y is Young's modulus); thus it can be adjusted by their composition, via tailoring the dielectric and mechanical properties. The generated voltage peak-to-peak measured was between 3.75 and 12.3 V mm(-1). The best result for the tested materials (i.e. harvested energy of 460 nJ or energy density of 4.6 mu J cm(-3), as a response to a micro-impulse of 0.017 kg m s(-1)) was obtained for a film having epsilon' = 3.6 and Y = 0.19 MPa.