Microchip
There is provided a microchip that is formed of a first substrate having a surface with a groove and a second substrate joined together and has a fluid circuit in the form of a cavity defined by the groove and a surface of the second substrate closer to the first substrate. The fluid circuit at least includes a detection portion having an optical path for transmitting light. The microchip includes at least one of a step defined by a groove formed in contact with at least one side surface of a groove of the first substrate that defines the optical path and a recess provided in the second substrate at a position opposite to the step.
1. A microchip formed of a first substrate having a surface with a groove and a second substrate joined together, and having a fluid circuit in a form of a cavity defined by said groove and a surface of said second substrate closer to said first substrate, said fluid circuit including a detection portion having an optical path for transmitting light, the optical path comprising a portion of the groove, said microchip comprising at least one of a step or a recess, wherein the step is adjacent a side surface of the portion of the groove that defines said optical path, the step having a height that is less than a height of the portion of the groove that defines the optical path, the recess being in said second substrate at a position opposite the side surface of the portion of the groove that defines the optical path.
2. The microchip according to claim 1 , wherein said first substrate has at least has two steps each of which is adjacent a different side surface of the portion of said groove defining said optical path.
3. The microchip according to claim 2 , wherein the side surfaces of the portion of said groove defining said optical path are, respectively, a plane of incidence of said light and a plane of emission of said light.
4. The microchip according to claim 1 , wherein said first substrate has said step and said second substrate does not have said recess.
5. The microchip according to claim 1 , wherein the portion of said groove defining said optical path has a depth of at least 1 mm and at most 2 mm.
6. The microchip according to claim 1 , wherein a portion of said groove defining said step has a depth of at most 0.5 mm.
7. The microchip according to claim 1 , wherein a portion of said groove defining said step has a depth of at most 0.1 mm.
8. The microchip according to claim 1 , wherein said first substrate is a transparent substrate.
9. The microchip according to claim 1 , wherein said second substrate is an opaque substrate.
10. The microchip according to claim 9 , wherein said second substrate is a black substrate.