Ceramic microarray spotting device for bioassay printing

A method of dispensing fluids from a ceramic plate comprising:

• providing a ceramic body having openings with hydrophilic surfaces including a plurality of reservoir feed holes, an open cavity over and in direct communication with a plurality of dispensing nozzles, and a plurality of channels connecting said plurality of reservoir feed holes to said plurality of dispensing nozzles, at least one channel of said plurality of channels being connected to at least two feed holes of said plurality of reservoir feed holes, said ceramic body comprising a plurality of sintered layered greensheets having a number of vertical and horizontal openings that together form said plurality of channels, such that, said plurality of channels comprise a matrix of channels residing at various heights throughout and within said ceramic body;
• providing fluids into said plurality of reservoir feed holes;
• providing an actuating means within said open cavity, said actuating means sealing and generating a pressure within said open cavity;
• forcing said pressure into said plurality of dispensing nozzles using said actuating means within said open cavity;
• actuating a surface of said fluids residing in each said plurality of reservoir feed holes via said pressure so that capillary action draws said fluids from said plurality of reservoir feed holes into said plurality of channels;
• transferring said fluids from said plurality of reservoir feed holes into said plurality of channels so that said fluids from said at least two feed holes are introduced into and intimately mixed in said at least one channel between said reservoir feed holes and said dispensing nozzles during transit at a creep flow of about Re<1 to form a mixture;
• transferring said fluids and said mixture into said plurality of dispensing nozzles having diameters less than about 50 microns;
• and
• simultaneously dispensing a micro array of drops per unit surface area of said fluids and said mixture from said plurality of dispensing nozzles onto a substrate.