Patent ID: 8523332

Claim:
Droplet deposition apparatus comprising: an array of fluid chambers, each fluid chamber defined by a pair of opposing chamber walls separated one from the other by a chamber wall separation, and in fluid communication with a nozzle for droplet ejection therefrom, each of said fluid chambers and said opposing chamber walls being elongate in a first direction, each of said opposing chamber walls deforming in shear mode in a chevron configuration upon application of an electric field thereto, wherein a top portion and a bottom portion of said chamber wall deform in opposite senses, and having an edge extending in said first direction; and a cover member joined to said edges of said chamber walls, thereby sealing one side of said chambers, the cover member having a cover thickness; wherein the ratio of cover thickness to chamber wall separation is less than or equal to 1:1; and wherein said nozzles are formed in said cover member and the cover member has a Young's modulus of less than or equal 100×10 9 N/m 2 .