Abstract: A piezoelectric device includes a membrane having fibres of a polyhydroxyalkanoate (PHA), having average diameter between 100 nm and 2000 nm, and at least one oxide having piezoelectric properties in a subdivided form having at least one average size between 1 nm and 100 nm. Preferably, the PHA fibres are produced by electrospinning. Advantageously, demonstrating good piezoelectric properties and considering that the piezoelectric device includes PHA, a biodegradable and biocompatible material, the device can be used in biological systems, for example in flexible micro-actuator systems for drug delivery and in the engineering of biological tissues (such as, for example, in pacemaker devices).

Abstract: The present invention concerns a process for preparing products having layers/films of silicon derivates comprising the following steps: a) Preparing a mould made of elastomeric material and having a plurality of grooves with mutual spacing in the range from 1 ?m to 1 mm; b) incubating the mould of step a) in a solution of silicateins in a range of temperatures from 2 to 10° C. and in a range of time from a few minutes to 103 hours; c) providing a target substrate of silicon or oxides thereof; d) transferring the silicateins from the mould to the said target substrate through soft lithography technique for a time period from a few seconds to 103 hours and removing the elastomeric mould; e) incubating the substrate with patterned silicateins of step d) in a solution of one or more precursors belonging to the class of silane compounds for a time period in a range from a few seconds to 103 hours in a temperature range from 2° C. to 25° C.