Filtration device, filtration method and filtration filter

A filtration device comprising:

• a filter assembly including a frame and a filter, the frame holding an outer peripheral portion of the filter to form an exposed contiguous inner section of the filter having a single contiguous outer periphery, the exposed inner section of the filter having openings through which a fluid can pass but a filtration target contained in the fluid cannot pass, the filter assembly being bendable between a flat position wherein the filter lies in a plane and various bent positions wherein the filter is bent, the frame fully surrounding and enclosing the exposed contiguous inner section of the filter when the filter assembly is in the flat position;
• an inanimate support structure that holds the frame in such a manner that that the frame, and with it the exposed contiguous inner section of the filter, is bent into a first bent position, which extends outside of the plane, by the inanimate support structure itself, the inanimate support structure holding the frame in such a manner that the fluid is free to pass through the entire exposed contiguous inner section of the filter but is not free to pass through the outer peripheral portion of the filter;
• and
• a fluid supply that supplies the fluid containing the filtration target to the exposed contiguous inner section of the filter while the frame is held in the first bent position by the inanimate support structure, the exposed contiguous inner section of the filter not being supported so that it is free to bend beyond the first bent position in a flow direction of the fluid as the fluid passes through the exposed contiguous inner section of the filter.