Abstract: The present invention relates to a layered structure, the method for obtaining it and its use as part of a piezoelectric ultrasonic transducer to operate in broadband pulse-echo mode and with high sensitivity and axial resolution in the presence of a pressurised gas at a pressure between 14 bar and 103 bar. Furthermore, the present invention relates to the transducer comprising said layered or stratified structure. Therefore, the present invention can be framed in the area of materials with applications such as sensors in ultrasonic systems.

Abstract: The present invention relates to a micro-device for selective and non-invasive separation of particles in polydispersed suspensions through the strategic use of ultrasounds, laminar flow and standing wave effects in a channel produced in a chip by means of microtechnology. Said device is a resonant multi-layer system with a modified lambda quarter-type treatment channel, which enables the particles to be channeled and separated in a flow inside the substrate channel without touching the walls of the device, in order to avoid problems of adherence. Said micro-device can be used in the field of biomedicine and/or biotechnology for the separation and concentration of cells, preferably human cells, applicable to research and medical processes for diagnosis and treatment.