Device for controlled distribution of micro- or nano-volumes of a liquid based on the piezoelectric effect in functionalized materials, without using external electric sources

摘要

Production and the distribution of pico and nano-drops, which are extracted by the effect of a strong electric field generated by pyroelectric effect, in particular, but not exclusively, from a sessile drop (a drop placed on a surface assumes a form termed “sessile”) or by a liquid film, and distributed on a dielectric substrate. The electric field is advantageously generated applying a heat source on the dielectric substrate or utilizing a laser source emitting in the infrared region. In this new approach, it is not necessary to use fixed electrodes, circuits, high tension generators or to design intentionally, and therefore to realize, pico- and nano-nozzles.

主权项

1. A method for the controlled distribution of pico- or nano-volumes of a liquid, comprising:
a first step of deposing the liquid as a film or multiple separated sessile drops on a top surface of a starting substrate; a second step of providing a destination substrate having a bottom surface spaced-apart from the starting substrate, the bottom surface of the destination substrate facing the top surface of the starting substrate; and a third step of varying the temperature of a first pyroelectric substrate, which is one of the starting substrate or the destination substrate and has a surface, to induce a surface charge density σ, such that the liquid on the top surface of the starting substrate, undergoing an electro-dynamic force, creates dispensing cones having volume V, wherefrom droplets detach and depose onto the bottom surface of the destination substrate, wherein the bottom surface of the destination substrate is set at a distance D from the top surface of the starting substrate, and the distance D is larger than a critical distance given by the following:
Dc=(1+θ/4)V1/3 wherein θ is a contact angle of one of the dispensing cones, and the contact angle is a starting angle of the one of the dispensing cones as measured with respect to the starting substrate, and V is the volume of the liquid of the one of the dispensing cones.