Micromachined two-dimensional array droplet ejectors

The method of operating a two-dimensional droplet ejector array of the type including a substrate with a plurality of wells, an elastic membrane closing one end of each of said plurality of wells, each elastic membrane including at least one aperture, membrane displacement means responsive to applied electrical signals for selectively displacing said membranes, and bulk displacement means associated with said fluid to provide bulk actuation of the fluid so that the bulk pressure wave is applied to all of membranes, whereby the bulk actuation and the selective membrane displacement combine to selectively eject droplets,

• comprising the steps of applying bulk actuation waves having an amplitude sufficient to form a meniscus at each aperture without ejecting droplets and selectively applying electrical signals to said membrane displacement means of sufficient amplitude to eject droplets.

The method of operating a two-dimensional droplet ejector array of the type including a substrate with a plurality of wells, an elastic membrane closing one end of each of said plurality of wells, each elastic membrane including at least one aperture, membrane displacement means responsive to applied electrical signals for selectively displacing said membranes, and bulk displacement means associated with said fluid to provide bulk actuation of the fluid so that the bulk pressure wave is applied to all of membranes, whereby the bulk actuation and the selective membrane displacement combine to selectively eject droplets,

• comprising the steps of applying bulk actuation waves having an amplitude sufficient to eject droplets from each of said apertures and selectively applying electrical signals to said membrane displacement means to inhibit ejection of droplets from selected apertures.

A two-dimensional array droplet ejector including:

• a body with a plurality of cylindrical wells,
• an elastic membrane closing one end of each of said plurality of wells, each elastic membrane including at least one aperture, and
• bulk displacement means in contact with said fluid in all of said wells to provide bulk actuation of the fluid so that the bulk pressure wave is applied to all of the membranes, whereby the bulk actuation ejects fluid droplets through said apertures.

A fluid droplet ejector comprising:

• a body having at least one cylindrical reservoir,
• an elastic membrane closing one end of the reservoir, said membrane including at least one aperture, and
• bulk displacement means associated with the material in said reservoir to actuate the fluid in said reservoir to deflect the membrane and eject fluid droplets through said aperture.