BIOCHIP DEVICE
A biochip device includes a stratified structure, a light coupler, and an optofluidic portion. The stratified structure includes a top layer having a refractive index n 1 , a bottom layer having a refractive index n 3 , and an intermediate layer between the top and bottom layers having a refractive index n 2 . The light coupler optically couples a light source and the top layer to generate waves that are guided in a plurality of directions inside the top layer. The optofluidic portion is supported on a surface of the top layer and includes a hybridizing chamber containing a hybridizing solution and pads supported on the surface of the top layer and situated within the hybridizing chamber. Probe molecules are deposited on the pads. The refractive index n 2 of the intermediate layer is greater than or equal to a highest index of refraction of the hybridizing chamber and the hybridizing solution.
1 . A biochip device comprising:
a stratified structure including a top layer having a refractive index n 1 , a bottom layer having a refractive index n 3 , and an intermediate layer disposed between the top layer and the bottom layer and having a refractive index n 2 ;
a light coupler optically coupling a light source and the top layer so as to generate waves that are guided in a plurality of directions inside the top layer; and
an optofluidic portion supported on a surface of the top layer and comprising a hybridizing chamber containing a hybridizing solution and pads supported on the surface of the top layer and situated within the hybridizing chamber, wherein probe molecules are deposited on the pads,
wherein the refractive index n 2 of the intermediate layer is greater than or equal to a highest index of refraction of the hybridizing chamber and the hybridizing solution.
2 . The biochip device of claim 1 , wherein the refractive index n 3 of the bottom layer is greater than the refractive index n 2 of the intermediate layer.
3 . The biochip device of claim 1 , further comprising chromophore elements deposited on the pads.
4 . The biochip device of claim 1 , wherein the light coupler comprises a light diffusing structure.
5 . The biochip device of claim 4 , wherein the light diffusing structure comprises structure having a disordered spatial distribution of refractive index.
6 . The biochip device of claim 4 , wherein the light diffusing structure comprises one of:
frosting with a grain size of 0.1 μm to 50 μm;
non-uniform metal or dielectric particles,
colloidal particles positioned in the top layer,
micro-cavities formed within the top layer, and
a layer of polytetrafluoroethylene on the top layer.
7 . The biochip device of claim 4 , wherein the light diffusing structure comprises diffusing particles in a matrix of a resin.
8 . The biochip of claim 7 , wherein the matrix is an acrylic resin, a glycerophthalic resin, or a fluoropolymer matrix.
9 . The biochip device of claim 7 , wherein the matrix has a refractive index that is less than the refractive index of the diffusing particles.
10 . The biochip device of claim 7 , wherein the diffusing particles comprise one of TiO 2 , Ta 2 O 5 , and BaSO 4 .
11 . The biochip device of claim 4 , wherein the light diffusing structure comprises micro-cavities having dimensions of 0.1 μm to 40 μm.
12 . The biochip device of claim 4 , wherein the light diffusing structure is deposited on a face of the top layer and comprises a layer of fluorophore material that responds to light excitation by generating fluorescent light that propagates in the top layer in the form of waves having an evanescent portion.
13 . The biochip device of claim 12 , wherein the fluorophore material comprises quantum dots, organic fluorophores, or fluorophores based on one of rare earth ions and luminescent ions.
14 . The biochip device of claim 1 , wherein the light coupler is disposed at one end of the stratified structure, and the optofluidic portion is disposed at an opposite end of the stratified structure.
15 . The biochip device of claim 1 , wherein the light coupler and the optofluidic portion are spaced apart, and wherein the intermediate layer and the bottom layer extend over the entire length of the top layer between the light coupler and the optofluidic portion.
16 . The biochip device of claim 1 , wherein the light coupler and the optofluidic portion are spaced apart, and wherein the bottom layer is formed of a material having an absorption coefficient α 3 that is greater than 2/L, where “L” is a distance between the light coupler and the optofluidic portion.
17 . The biochip device of claim 16 , wherein L is about 1 cm.
18 . The biochip device of claim 1 , wherein the stratified structure is made of a polymer.
19 . The biochip device of claim 1 , wherein n 1 =1.55, n 2 =1.42, and n 3 =1.55.
20 . The biochip device of claim 1 , wherein the top layer has a thickness z 1 is equal to 5 μm to 50 μm, the intermediate layer has a thickness z 2 that is greater than 3 μm, and the bottom layer has a thickness z 3 that is greater than or equal to z 1 .
21 . The biochip device of claim 20 , wherein z 3 is about 500 μm.
22 . The biochip device of claim 1 , wherein the bottom layer comprises an organic or inorganic dye dispersed in the bottom layer.