Microvascular network device

A method of producing a microvascular network device comprising:

• applying onto a first substrate an energy sensitive composition to produce an energy sensitive coating;
• patternwise exposing said energy sensitive coating with an energy source to produce a coating having exposed and unexposed regions;
• contacting a developer and said coating having exposed and unexposed regions to selectively remove said exposed regions to produce a patterned layer;
• curing said patterned layer;
• etching said patterned layer and removing said excess energy sensitive coating to produce a patterned substrate;
• providing transparent liquid elastomer to said patterned substrate and thereafter baking said elastomer patterned substrate to produce a molded microchannel cast structure;
• removing said molded microchannel cast structure from said patterned substrate;
• and
• capping said molded microchannel cast structure with an elastomer-coated second substrate, thereby sealing said microchannels of said microchannel cast structure to provide said microvascular network device.

A method for separating blood cells or evaluating the flow of blood cells in vitro comprising:

• flowing a liquid sample medium selected from the group consisting of:
• whole blood, red blood cells, white blood cells, and any combinations thereof, through a microvascular network device wherein said microvascular network device comprises:
• a substrate;
• at least one microchannel;
• at least one opening to said microchannel for sample entry;
• at least one opening to said microchannel for sample exit;
• and
• an aspirator which causes said sample to traverse said microchannel.