Microfluidic device
A microfluidic device, a diagnostic device including the microfluidic device and a method for making the microfluidic device are provided. The microfluidic device includes: (i) a transparent substrate comprising a cavity, the cavity opening up to a top of the transparent substrate; (ii) a transparent layer covering the cavity, and (iii) a semiconductor substrate over the transparent layer and the transparent substrate, wherein the semiconductor substrate comprises a through hole overlaying the cavity and exposing the transparent layer.
1. A method for making a microfluidic device, the method comprising:
(a) providing a transparent substrate comprising a cavity, the cavity opening up to a top of the transparent substrate;
(b) providing a semiconductor substrate;
(c) forming, over the transparent substrate, a transparent layer covering the cavity;
(d) after step (c), bonding the transparent substrate to the semiconductor substrate by anodic bonding in such a way that the transparent layer is present between the semiconductor substrate and the transparent substrate; and
(e) etching a through hole through the semiconductor substrate to expose the transparent layer covering the cavity.
2. The method according to claim 1 , wherein step c comprises patterning the transparent layer.
3. The method according to claim 1 , wherein step (c) comprises transferring the transparent layer from an auxiliary substrate to the transparent substrate.
4. The method according to claim 1 , wherein the semiconductor substrate comprises a microfluidic channel and wherein step d comprises bonding the semiconductor substrate to the transparent layer in such a way that the microfluidic channel is fluidically coupled to the cavity.
5. The method according to claim 1 , wherein the semiconductor substrate comprises silicon.
6. The method according to claim 1 , wherein the transparent substrate comprises glass.
7. The method according to claim 1 , wherein the transparent layer comprises a polymer, a silicon nitride or a silicon oxide.
8. The method according to claim 1 , wherein the microfluidic device comprises a microfluidic channel fluidically coupled to the cavity.
9. The method according to claim 8 , wherein the microfluidic channel is a capillary microfluidic channel.