Abstract: Described are stator arrays for multi-valve systems used in different chromatographic applications. Also described is a mounting assembly for a multi-valve system that includes the stator array. Each stator array has a stator body having a first stator surface and a second stator surface. Each stator surface has a plurality of stator ports and is configured to engage a rotor surface of a rotary valve actuator. A fluid channel inside the stator body couples one of the stator ports of the first stator surface to one of the stator ports of the second stator surface. The fluid channel may be a microfluidic channel. A solid-state diffusion bonding process in which two or more parallel layers of material are joined together may be used to fabricate the stator body. Complex fluid channel networks may be formed using many fluid channels formed in multiple layers within the stator body.