An electrohydrodynamic print head has a plurality of nozzles arranged in a plurality of wells. Extraction electrodes are located around the wells at a level below the nozzles. Further, shielding electrodes are located around the wells at a level below the extraction electrodes. For each well, there are several such shielding electrodes located at different angular positions. This allows to use the shielding electrodes for laterally deflecting the ink after its ejection from the nozzles.

The disclosure provides a method of manipulating droplets in an electro-wetting on dielectric (EWOD) device. Electro-wetting electrodes of the EWOD device are selectively actuated to: cause first and second droplets in a fluid medium in the fluid chamber of the EWOD device to contact each other to form a droplet interface bilayer, the first droplet containing fluid of a first composition including a first solute species and the second droplet containing fluid of a second composition different to the first composition, maintain the first and second droplets contacting each other to maintain the droplet interface bilayer and thereby allow the first solute species to pass from the first droplet to the second droplet via the DIB; and cause the first droplet to separate from the second droplet. This method aspect results in transfer of solute from the first droplet to the second droplet. This provides a convenient way of altering the concentration of a particular component or components in a fluid droplet within an EWOD device. This allows, for example, an undesired solute species to be extracted from a reaction droplet or the undesired solute species to be diluted in the reaction droplet before the droplet undergoes further reaction steps.

An apparatus for generating a droplet of a liquid metal material in a metal additive manufacturing process includes a nozzle configured to eject the droplet of the liquid metal material, the nozzle including a conductive solid. The apparatus also includes a voltage source configured to apply voltage between the conductive solid and the liquid metal material to modify a contact angle between an inner wall of the nozzle and the liquid metal material within the nozzle. The apparatus also includes a controller configured to modify the voltage from the voltage source to modify the contact angle and generate the droplet of the liquid metal material.

A liquid ejection head includes an ejection orifice through which a liquid is ejected, a first liquid flow path which is in communication with the ejection orifice and through which the liquid flows, a second liquid flow path which is in communication with the ejection orifice on the opposite side of the first liquid flow path with respect to the ejection orifice 12 and through which the liquid flows, a first electrode positioned in the first liquid flow path 13, and a second electrode which is positioned in the second liquid flow path and generates an electro-osmotic flow in the liquid together with the first electrode.

A liquid ejection head 1 includes an ejection orifice 12 through which a liquid is ejected, a first liquid flow path 13 which is in communication with the ejection orifice 12 and through which the liquid flows, a second liquid flow path 14 which is in communication with the ejection orifice 12 on the opposite side of the first liquid flow 13 with respect to the ejection orifice 12 and through which the liquid flows, a first electrode 21 positioned in the first liquid flow path 13, and a second electrode 22 which is positioned in the second liquid flow path 14 and generates an electro-osmotic flow in the liquid together with the first electrode 21.

Methods are provided for manipulating droplets. The methods include providing the droplet on a surface comprising an array of electrodes and a substantially co-planer array of reference elements, wherein the droplet is disposed on a first one of the electrodes, and the droplet at least partially overlaps a second one of the electrodes and an intervening one of the reference elements disposed between the first and second electrodes. The methods further include activating the first and second electrodes to spread at least a portion of the droplet across the second electrode and deactivating the first electrode to move the droplet from the first electrode to the second electrode.

A microfluidic device having a substrate with an electrically conductive element made using a conductive ink layer underlying a hydrophobic layer.

A microfluidic device having a substrate with an electrically conductive element made using a conductive ink layer underlying a hydrophobic layer.

A microfluidic device having a substrate with an electrically conductive element made using a conductive ink layer underlying a hydrophobic layer.

An apparatus for generating a droplet of a liquid metal material in a metal additive manufacturing process includes a nozzle configured to eject the droplet of the liquid metal material, the nozzle including a conductive solid. The apparatus also includes a voltage source configured to apply voltage between the conductive solid and the liquid metal material to modify a contact angle between an inner wall of the nozzle and the liquid metal material within the nozzle. The apparatus also includes a controller configured to modify the voltage from the voltage source to modify the contact angle and generate the droplet of the liquid metal material.