Filters for liquid flow based devices and systems

A filter, comprising:

• an inlet side;
• an outlet side;
• and
• a body having a thickness along a main axis between the inlet side and the outlet side, and a planar area in a transverse plane orthogonal to the main axis, the body comprising:
• a first substrate comprising a first outside surface at the inlet side, a first inside surface, and an array of inlet holes passing through the first substrate from the first outside surface to the first inside surface;
• a second substrate comprising a second outside surface at the outlet side, a second inside surface facing the first inside surface, and an array of outlet holes passing through the second substrate from the second inside surface to the second outside surface, wherein the outlet holes are not in direct fluid communication with the inlet holes;
• and
• a channel region comprising a plurality of channels extending at an angle to the main axis, each channel communicating with at least one of the inlet holes and at least one of the outlet holes, wherein:
• the filter comprises a plurality of fluid flow paths through the body from the inlet side to the outlet side;
• each flow path runs from at least one of the inlet holes to at least one of the channels, and from the at least one channel to at least one of the outlet holes;
• and
• each flow path comprises a first turn between the at least one inlet hole and the at least one channel, and a second turn between the at least one channel and the at least one outlet hole.