A microfluidic device, having a containment body accommodating a plurality of ejecting elements arranged adjacent to each other. Each ejecting element has a liquid inlet, a containment chamber, a piezoelectric actuator and an ejection nozzle. The piezoelectric actuators of each ejecting element are connected to a control unit configured to generate actuation signals and to be integrated in the containment body.

A liquid droplet forming device for stably forming and ejecting a liquid droplet of a dispersion liquid containing settling particles includes an ejection head that ejects a liquid droplet of a liquid containing settling particles, and a control unit. The control unit controls a behavior of the ejection head by supplying an electrical signal. The ejection head includes a liquid holding portion that holds the liquid, a film-like member that has an ejection hole for ejecting the liquid droplet and that forms a liquid chamber, which holds the liquid, together with the liquid holding portion, and vibration applying means for vibrating the film-like member based on the electrical signal. The electrical signal includes an ejection signal for forming the liquid droplet by vibrating the film-like member, a stirring signal for vibrating the film-like member and a micro-vibration signal.

A liquid discharging device to be used with a liquid dispensing apparatus includes a discharging portion configured to discharge a liquid based on a control signal from the liquid dispensing apparatus on which the liquid discharging device is mounted, and a sheet material having a characteristic configured to be changed by the liquid dispensing apparatus after a discharge of the liquid by the discharging portion.

A jetting device includes an ejection unit arranged to eject a droplet of a liquid. The ejection unit includes a nozzle, a liquid duct connected to the nozzle, and an electro-mechanical transducer arranged to create an acoustic pressure wave in the liquid in the duct. The jetting device further includes a filter arranged to filter the liquid being supplied into the duct and a filter status detection system arranged to detect an obstruction status of the filter by measuring a property of the liquid in the duct. The filter status detection system includes a circuit configured for measuring the electric response of the transducer, for recording changes in the electric response that represent pressure fluctuations induced by the acoustic wave in the form of a time-dependent function, and for judging the obstruction status of the filter on the basis of that function.

The microfluidic device has a plurality of ejector elements. Each ejector element includes a first region, accommodating a first fluid flow channel and an actuator chamber; a second region, accommodating a fluid containment chamber; and a third region, accommodating a second fluid flow channel. The fluid containment chamber is fluidically coupled to the first and to the second fluid flow channels. The second region is formed from a membrane layer, from a membrane definition layer, mechanically coupled to the membrane layer and having a membrane definition opening, and a fluid chamber defining body, mechanically coupled to the membrane definition layer and having a chamber defining opening, with a width greater than the width of the membrane definition opening. The width of the membrane is thus defined by the width of the chamber defining opening.

According to an embodiment, an inkjet head includes a nozzle that ejects ink, an ink pressure chamber that connects to the nozzle, an actuator that changes a volume of the ink pressure chamber, and an actuator driving circuit that drives the actuator with a driving waveform. The driving waveform includes an ejection pulse portion that changes from a first voltage to a second voltage at which the ink pressure chamber expands and then changes from the second voltage to a third voltage at which the ink pressure chamber contracts so as to eject the ink from the nozzle. The third voltage is between that of the first and second voltages in potential level. The potential difference between the second and third voltages is greater than the potential difference between the third and first voltages.

An ink jet head includes a pressure chamber connected to a nozzle, an actuator configured to cause liquid in the pressure chamber to be ejected from the nozzle by deforming a wall of the pressure chamber, and a drive circuit configured to apply voltage to the actuator to drive the actuator. When a droplet of the liquid is ejected from the nozzle, the voltage applied to the actuator is changed from a first value to a second value that causes the pressure chamber to expand, and then changed from a third value that is equal to the second value or between the first value and the second value to the first value after a time period , which is a primary natural oscillation period of the actuator when the pressure chamber and the nozzle are filled with the liquid.

A process of manufacturing droplet jetting devices includes bonding together a nozzle wafer defining nozzles of the jetting devices, a membrane wafer carrying, on a membrane, actuators for generating pressure waves in a liquid in pressure chambers that are connected to the nozzles, and a distribution wafer forming a distribution layer that defines supply lines for supplying the liquid to the pressure chambers from a liquid reservoir formed on a side of the distribution layer opposite to the membrane wafer; and dicing the bonded wafers. The distribution layer has a thickness larger than the thickness of each of the other two wafers. A restrictor for controlling the inertance of the liquid supply line is formed through the distribution layer in a direction normal to the plane of that layer.

A liquid droplet ejecting apparatus includes a liquid container including an upper opening for receiving liquid and a lower opening for supplying the liquid, the upper opening being larger than the lower opening, and a liquid ejection chip that is fixed to a lower surface of the liquid container, and includes a pressure chamber formed therein, a nozzle to eject liquid from the pressure chamber, and an actuator disposed adjacent to the nozzle. An opening of the pressure chamber is in fluid communication with the lower opening and is entirely included in an area of the lower opening.

A microfluidic device, having a containment body accommodating a plurality of ejecting elements arranged adjacent to each other. Each ejecting element has a liquid inlet, a containment chamber, a piezoelectric actuator and an ejection nozzle. The piezoelectric actuators of each ejecting element are connected to a control unit configured to generate actuation signals and to be integrated in the containment body.