Microfluidic capsule

A microfluidic capsule comprising:

• a top lid in the form of a lid sheet comprising a light window;
• a middle piece comprising:
• a middle sheet having a perimeter and comprising at least one fluid inlet and at least one fluid outlet in the form of through holes in said middle sheet and a light window positioned to be aligned with said light window of said top lid when said top lid is attached to said middle piece and having a circumferential or circumferentially distributed wall around its perimeter;
• multiple raised walls circumferentially distributed around said perimeter of said middle sheet and separated by raised connection structures having a height relative said middle sheet that is lower than a height of said multiple raised walls relative said middle sheet;
• at least one support pillar attached to said middle sheet at a position between said perimeter of said middle sheet and said perimeter of said light window of said middle piece, wherein the ends of said multiple raised walls said circumferential or circumferentially distributed wall and said at least one support pillar facing opposite to said middle sheet are arranged to be attached to said top lid;
• and
• at least one inlet connector in the form of a tube having a first end connected to said at least one fluid inlet and having a second, opposite end protruding out through an opening of a wall of said multiple raised walls;
• and
• a bottom piece comprising:
• a bottom sheet having a perimeter and a light window allowing visual inspection through said light window of said bottom piece, said light window of said top lid and said light window of said middle piece when said bottom piece is attached to said middle piece and said top lid;
• multiple snap-fit structures circumferentially distributed around said perimeter of said bottom sheet and extending from said bottom sheet and positioned to be aligned with said raised connection structures to lock said bottom piece to said middle piece;
• and
• a transparent cover sheet, wherein said microfluidic capsule is designed to enclose a microfluidic substrate between said bottom piece and said middle piece so that an open culture chamber of said microfluidic substrate aligned with said light windows of said top lid, said middle piece and said bottom piece becomes closed by said transparent cover sheet and at least one fluid channel of said microfluidic substrate (400) becomes connected to said at least one fluid inlet and said at least one fluid outlet.