Microfluidic device for spraying very small drops of liquids
A microfluidic device has a chamber; a fluidic access channel in fluidic connection with the chamber; a plurality of nozzle apertures in fluidic connection with the chamber; and an actuator, operatively coupled to the fluid containment chamber and configured to cause ejection of drops of fluid through the nozzle apertures in an operating condition of the microfluidic device. The chamber has an elongated shape, with a length and a maximum width, wherein an aspect ratio between the length and the maximum width of the chamber is at least 3:1. The nozzle apertures are configured to generate, in use, a plurality of drops having a total drop volume, wherein a ratio total drop volume to a chamber volume is at least 15%.
1 . A microfluidic device comprising:
a plurality of chambers, the chambers having an elongated shape;
a plurality of fluidic access channels in fluidic connection with the plurality of chambers, respectively;
a plurality of nozzle apertures in fluidic connection with the plurality of chambers, respectively; and
a plurality of actuators operatively coupled to the plurality of chambers, respectively, and configured to cause ejection of drops of fluid through the plurality of nozzle apertures in an operating condition of the microfluidic device;
a chamber layer that forms the plurality of chambers;
a nozzle layer on the chamber layer, the nozzle layer forms a plurality of nozzle openings,
each of the plurality of chambers being delimited by a lateral wall having a plurality of indentations and protrusions; and
the plurality of nozzle openings being offset with respect to the plurality of chambers, with each of the plurality of nozzle openings extending between two adjacent chambers and intersecting indentations of the two adjacent chambers,
wherein the plurality of nozzle apertures are formed at intersection areas of the plurality of nozzle opening and the plurality of indentations.
2 . The microfluidic device according to claim 1 , wherein each of the plurality of chambers has a rectangular or oval base shape.
3 . The microfluidic device according to claim 1 , wherein each of the plurality of chambers is delimited by a first base, a second base, and a lateral wall,
the first and second bases extending along a first and a second direction, respectively,
the second direction transverse to the first direction,
a length and a width of each of the plurality of chambers extending in the first and second directions, respectively,
the lateral wall extending along a third direction, transverse to the first and second directions,
a height of each of the plurality of chambers extending in the third direction.
4 . The microfluidic device according to claim 3 , wherein
each of the plurality of chambers has a chamber volume, and
the plurality of nozzle apertures are configured to generate, in use, a plurality of drops having a total drop volume, and
a ratio of the total drop volume to chamber volume is at least 15%.
5 . The microfluidic device according to claim 3 , further comprising:
a base body portion, the base body portion forming the first base and accommodating the plurality of actuators, the nozzle layer forming the second base.
6 . The microfluidic device according to claim 5 , wherein the chamber layer includes a first layer and a second layer extending on the first layer, the first layer delimiting a lower chamber aperture, the second layer delimiting an upper chamber aperture, the lower chamber aperture having a smaller area than the upper chamber aperture, wherein the first layer extends on the base body portion.
7 . The microfluidic device according to claim 5 , wherein the chamber layer and the nozzle layer are polymeric layers, or the chamber layer is a polymeric layer and the nozzle layer is a silicon wafer.
8 . The microfluidic device according to claim 1 , wherein the plurality of actuators are heaters.
9 . The microfluidic device according to claim 1 , wherein the plurality of nozzle openings have a larger area than the plurality of chambers.
10 . The microfluidic device according to claim 1 , wherein an aspect ratio between a length and a width of each of the plurality of chambers is at least 3:1.
11 . A microfluidic device comprising:
a plurality of emitter groups, each emitter group comprising:
a plurality of chambers, the chambers having an elongated shape;
a plurality of fluidic access channels in fluidic connection with the plurality of chambers, respectively;
a plurality of nozzle apertures in fluidic connection with the plurality of chambers, respectively; and
a plurality of actuators operatively coupled to the plurality of chambers, respectively, and configured to cause ejection of drops of fluid through the plurality of nozzle apertures in an operating condition of the microfluidic device;
a chamber layer that forms the plurality of chambers;
a nozzle layer on the chamber layer, the nozzle layer forms a plurality of nozzle openings,
each of the plurality of chambers being delimited by a lateral wall having a plurality of indentations and protrusions; and
the plurality of nozzle openings being offset with respect to the plurality of chambers, with each of the plurality of nozzle openings extending between two adjacent chambers and intersecting indentations of the two adjacent chambers,
wherein the plurality of nozzle apertures are formed at intersection areas of the plurality of nozzle opening and the plurality of indentations.
12 . The microfluidic device according to claim 11 , wherein each of the plurality of chambers is delimited by a first base, a second base, and a lateral wall,
the first and second bases extending along a first and a second direction, respectively,
the second direction transverse to the first direction,
a length and a width of each of the plurality of chambers extending in the first and second directions, respectively,
the lateral wall extending along a third direction, transverse to the first and second directions,
a height of each of the plurality of chambers extending in the third direction.
13 . The microfluidic device according to claim 12 , wherein
each of the plurality of chambers has a chamber volume, and
the plurality of nozzle apertures are configured to generate, in use, a plurality of drops having a total drop volume, and
a ratio of the total drop volume to chamber volume is at least 15%.
14 . The microfluidic device according to claim 12 , further comprising:
a base body portion, the base body portion forming the first base and accommodating the plurality of actuators, the nozzle layer forming the second base.
15 . The microfluidic device according to claim 14 , wherein the chamber layer includes a first layer and a second layer extending on the first layer, the first layer delimiting a lower chamber aperture, the second layer delimiting an upper chamber aperture, the lower chamber aperture having a smaller area than the upper chamber aperture, wherein the first layer extends on the base body portion.
16 . The microfluidic device according to claim 14 , wherein the chamber layer and the nozzle layer are polymeric layers, or the chamber layer is a polymeric layer and the nozzle layer is a silicon wafer.
17 . The microfluidic device according to claim 11 , wherein the plurality of actuators are heaters.
18 . The microfluidic device according to claim 17 , wherein the heaters within the same emitter group are coupled together.
19 . The microfluidic device according to claim 18 , wherein the heaters within the same emitter group are coupled between a firing circuit, supplying firing pulses, and ground.