CN101825743A

CN101825743A - Fluid optical waveguide structure

Info

Publication number: CN101825743A
Application number: CN 201010128851
Authority: CN
Inventors: 黎永前; 丁丽娟; 王宁博
Original assignee: Northwestern Polytechnical University
Current assignee: NANTONG JINNIU MACHINERY MANUFACTURE CO., LTD.
Priority date: 2010-03-19
Filing date: 2010-03-19
Publication date: 2010-09-08
Anticipated expiration: 2030-03-19
Also published as: CN101825743B

Abstract

The invention discloses a fluid optical waveguide structure, which is based on the principle that the refractive index of fluid changes along with the temperature and adopts a method of electrode heating to form the fluid optical waveguide. The fluid optical waveguide comprises a substrate I, a structure layer and a substrate II, wherein the structure layer is provided with a microtube of which two ends are respectively communicated with an input port 5 and an output port 7; a pair of metal electrodes are respectively positioned at the corresponding positions of the substrate I and the substrate II, or positioned on two inner walls of the structure layer, or coat the whole microtube; the position on the substrate I corresponding to the positions of the input port 5 and the output port 7 on the structure layer are distributed with holes; and in order to ensure that the metal electrodes are insulated with the fluid, a thin polymer film can be covered on the metal electrodes. Because any fluid at the same type can be used in the invention, the material selectivity of the fluid optical waveguide is more flexible; and by the simple control of a circuit, the invention realizes the stable light transmission in the fluid optical waveguide, thereby providing a simple and convenient tool for the optical detection of the biological cells and large biological molecules.

Description

Fluid optical waveguide structure

Affiliated field

The present invention relates to a kind of fluid optical waveguide structure, belong to the optical waveguide field in micromechanics electronic system (MEMS), integrated optics field.

Prior art

Optical waveguide can provide the liquid environment that relies in existence for biological detection, and the physical channel of optical information transmission is provided simultaneously, has obtained extensive studies in recent years.The structure of the optical waveguide in the research comprises three kinds at present: (1) ducting layer material is a fluid, and covering layer material is a solid; (2) the ducting layer material is a fluid, and covering layer material is a fluid; (3) the ducting layer material is a fluid, and covering layer material is a gas.

The optical waveguide that constitutes by fluid ducting layer and solid overlayer.Proposed a kind of fluid optical waveguide structure that is made of fluid ducting layer and solid overlayer in the Chinese patent (CN200710044173.3), the selective refraction rate makes light propagate in fluid ducting layer experiences total internal reflection greater than the fluid of solid overlayer refractive index; Similar structures can also be referring to people such as the Datta article that the 3rd volume 788-795 page or leaf was delivered on IEEE SENSORS JOURNAL in 2003.Perhaps the solid overlayer utilizes principle of interference to carry out light transmission, people such as Yin have proposed a kind of fluid optical waveguide structure that is made of fluid ducting layer and solid overlayer in the article of delivering on the APL 85 3477-3479 pages or leaves in 2004, solid overlayer refractive index is greater than the fluid refracting rate, and the intratectal coherent interference of multilayer makes light interfere propagation at overlayer.The article that can also on the 13rd phase on the OPTICSEXPRESS in 2005 No. 23, deliver referring to people such as Yin.The optical waveguide that the solid overlayer is formed must be selected suitable material, and perhaps complicated manufacturing process makes and satisfies the condition of solid overlayer refractive index less than fluid.

The optical waveguide that constitutes by fluid ducting layer and gas blanket.People such as Yang Seung Man propose a kind of optical waveguide that is made of fluid ducting layer and gas blanket in European patent (KR20090100956).

By the optical waveguide that fluid ducting layer and fluid overlayer constitute, adopt the ducting layer fluid of refractive index equally greater than overlayer fluid refracting rate, satisfy light and propagate in fluid ducting layer generation total reflection.The United States Patent (USP) (US2009/0097808A1) that people such as Wolfe obtain has proposed to have little coefficient of diffusion when two kinds of fluids are in laminar condition, forms ducting layer and tectal fluid optical waveguide structure respectively by the different fluid of refractive index value.Chinese patent (200680005292) has proposed a kind of optical waveguide of being made up of two kinds of different immiscible fluids of electric conductivity, the big fluid of refractive index is as ducting layer, and this structure can change the interphase of liquid to change light-transfer characteristic by electrowetting effect.People such as Tang have described a kind of fluid optical waveguide structure of being made up of the same fluid of different temperatures in the article of delivering on the APL 88,061112 in 2006.The article that similar structures can also be delivered on the APL 93,193901 in 2008 referring to people such as Li.The optical waveguide of forming by the fluid overlayer, because the diffusion of molecule between the fluid, and the instability in temperature field, and influence the stable propagation of light in optical waveguide.

Summary of the invention

The objective of the invention is: the optical waveguide that is made of the solid overlayer is restricted to solid overlayer and fluid ducting layer material at having now, and the optical waveguide that is made of the fluid overlayer is propagated unsettled present situation because of the light that the diffusion of molecule between the fluid causes, propose a kind of simple in structurely, can in the fluid microchannel, realize stable fluid optical waveguide structure and the application process of propagating thereof of light.

Consult accompanying drawing 1 and accompanying drawing 2, technical scheme of the present invention is: a kind of fluid optical waveguide structure, comprise substrate I 1, structural sheet 2 and substrate II 3 successively, the microchannel parallel with substrate I 1 and substrate II 3 arranged on the structural sheet 2, be full of fluid in the microchannel, its two ends are communicated with input port 5 and delivery outlet 7 respectively, and pair of metal electrodes 4 is in respectively on substrate I 1 and the substrate II 3 on the corresponding position with the fluid in the direct heating microchannel; Metal electrode 4 also can be on two inwalls of structural sheet 2, and perhaps metal electrode 4 coats whole microchannel; On the substrate I 1 with structural sheet 2 on be furnished with perforate on input port 5 and the delivery outlet 7 corresponding positions, be used for the input and output of fluid.

In order to guarantee metal electrode 4 and fluid insulation,, consult accompanying drawing 7-9 at metal electrode 4 surface coverage thin polymer films 8.

The invention has the beneficial effects as follows: form optical waveguide with the principle that the variation of fluid temperature (F.T.) changes based on the fluid refracting rate.Cause metal electrode 4 temperature to raise by metal electrode 4 being applied steady current, because heat transferred, raise with metal electrode 4 fluid in contact regional temperatures in the microchannel, make the refractive index of this regional fluid reduce, fluid in microchannel forms the zone with different refractivity, the zone that contacts with metal electrode 4 constitutes fluid overlayer 11, and the fluid mass that is clipped between the fluid overlayer constitutes fluid ducting layer 12; Owing to have refractive index gradient between fluid ducting layer 12 and the fluid overlayer 11, make light in fluid ducting layer 12, stablize and propagate.

The fluid optical waveguide structure that the present invention proposes, the heated by electrodes method at employing fluid microchannel edge makes the refractive index of contact electrode regional fluid change, and forms the fluid overlayer.In microchannel, use any fluid of the same race to prepare optical waveguide, make that the material selectivity of optical waveguide is more flexible; By the control of simple circuit, realize the stable propagation of light in optical waveguide, for the optical detection of biological cell and biomacromolecule provides easy instrument.

Summary of drawings

Fig. 1 is a kind of structural representation of optical waveguide;

Fig. 2 is the cross sectional representation of optical waveguide 6 among the embodiment 1;

Fig. 3 is the cut-open view in B-B cross section among Fig. 2;

The graph of relation of distance between the variations in refractive index of Fig. 4 fluid 9 when metal electrode 4 applied steady current and fluid 9 and the metal electrode 4;

Fig. 5 A-C is the synoptic diagram of relative position relation between fluid ducting layer 12 and the fluid overlayer 11 among the embodiment 1;

Fig. 6 is the synoptic diagram that light beam 10 is propagated in optical waveguide 6;

Fig. 7 is the transversal synoptic diagram of optical waveguide 6 among the embodiment 2;

Fig. 8 is the cut-open view in C-C cross section among Fig. 7;

Fig. 9 is the cross sectional representation of optical waveguide 6 among the embodiment 3;

Among the figure: 1-substrate I, 2-structural sheet, 3-substrate II, 4-metal electrode, 5-input port, 6-optical waveguide, 7-delivery outlet, 8-thin polymer film, 9-fluid, 10-light beam, 11-fluid overlayer, 12-fluid ducting layer.

Embodiment

Embodiment 1:

Consult accompanying drawing 1 and accompanying drawing 2, the fluid optical waveguide structure that the present invention proposes comprises substrate I 1, structural sheet 2 and substrate II 3 successively, and described substrate I 1 and substrate II 3 materials are PI, and structural sheet 2 materials are PDMS; The microchannel parallel with substrate I 1 and substrate II 3 arranged on the structural sheet 2, be full of deionized water in the microchannel, its two ends are communicated with input port 5 and delivery outlet 7 respectively, and a pair of nickel metal electrode 4 is in respectively on substrate I 1 and the substrate II 3 on the corresponding position with the fluid in the direct heating microchannel.

Present embodiment adopts the method for heated by electrodes to form optical waveguide.Nickel metal electrode 4 is applied steady current, cause nickel metal electrode 4 temperature to raise, because heat transferred, the deionized water regional temperature that contacts with nickel metal electrode 4 in the microchannel raises, and makes the refractive index of this zone deionized water reduce, and the deionized water in microchannel forms the zone with different refractivity, consult accompanying drawing 4, the zone that contacts with nickel metal electrode 4 constitutes fluid overlayer 11, and the deionized water zone that is clipped between the fluid overlayer 11 constitutes fluid ducting layer 12, consults accompanying drawing 5.Owing to have refractive index gradient between fluid ducting layer 12 and the fluid overlayer 11, make light beam 10 in fluid ducting layer 12, propagate according to the mode of accompanying drawing 6.

Consult accompanying drawing 4 and accompanying drawing 5, when to substrate I 1 when nickel metal electrode 4 on the substrate II 3 applies identical steady current, nickel metal electrode 4 temperature on substrate I 1 and the substrate II 3 raise synchronously, the transfer rate of heat is identical, therefore form the identical fluid overlayer 11 of height h, fluid ducting layer 12 is in the microchannel centre position; If it is inequality to be applied to the steady current of the nickel metal electrode 4 on substrate I 1 and the substrate II 3, cause the speed difference that two nickel metal electrodes, 4 temperature raise, cause the transfer rate of heat inequality, therefore form height h fluid overlayer 11 inequality, fluid ducting layer 12 departs from the microchannel centre position.The steady current of the nickel metal electrode 4 on being applied to substrate I 1 when being applied to the steady current of the nickel metal electrode 4 on the substrate II 3, fluid ducting layer 12 downward biases from, shown in accompanying drawing 5B; The steady current of the nickel metal electrode 4 on being applied to substrate I 1 is when being applied to the steady current of the nickel metal electrode 4 on the substrate II 3, and fluid ducting layer 12 upwards departs from, shown in accompanying drawing 5C.Therefore, be applied to the steady current size of the nickel metal electrode 4 on substrate I 1 and the substrate II 3, change the relative position relation between fluid ducting layer 12 and the fluid overlayer 11, realize light beam modulation spatially by control.

Because a pair of nickel metal electrode 4 is in respectively on substrate I 1 and the substrate II 3 on the corresponding position, when nickel metal electrode 4 is applied steady current, the refractive index that causes the deionized water that is in contact with it in the microchannel changes, only on perpendicular to substrate I 1 and substrate II 3 directions, satisfy the refractive index of the refractive index of fluid ducting layer 12, therefore form slab guide greater than fluid overlayer 11.

Embodiment 2:

Consult accompanying drawing 7 and accompanying drawing 8, the fluid optical waveguide structure that the present invention proposes comprises substrate I 1, structural sheet 2 and substrate II 3 successively, and described substrate I 1 and substrate II 3 materials are PMMA, and structural sheet 2 materials are PDMS; The microchannel parallel with substrate I 1 and substrate II 3 arranged on the structural sheet 2, be full of ethanol in the microchannel, its two ends are communicated with input port 5 and delivery outlet 7 respectively, and a pair of copper metal electrode 4 is in respectively on two inwalls of structural sheet 2 with the fluid in the direct heating microchannel.In order to guarantee the insulation of metal electrode 4 and ethanol, be the thin polymer film 8 of polyvinyl alcohol (PVA) at metal electrode 4 surface coating materials.

Present embodiment adopts the method for heated by electrodes to form optical waveguide.Copper metal electrode 4 is applied steady current, cause copper metal electrode 4 temperature to raise, for heat transferred, the ethanol regional temperature that contacts with copper metal electrode 4 in the microchannel raises, make the refractive index of this zone ethanol reduce, ethanol in microchannel forms the zone with different refractivity, and the zone that contacts with copper metal electrode 4 constitutes fluid overlayer 11, and the ethanol zone that is clipped between the fluid overlayer 11 constitutes fluid ducting layer 12.

Because copper metal electrode 4 is on two inwalls of structural sheet 2, when copper metal electrode 4 is applied steady current, the refractive index that causes the ethanol that is in contact with it in the microchannel changes, only on perpendicular to the inwall direction, satisfy the refractive index of the refractive index of fluid ducting layer 12, therefore form slab guide greater than fluid overlayer 11.

Embodiment 3:

Consult accompanying drawing 9, the fluid optical waveguide structure that the present invention proposes comprises substrate I 1, structural sheet 2 and substrate II 3 successively, and described substrate I 1 and substrate II 3 materials are glass, and structural sheet 2 materials are SU-8; The microchannel parallel with substrate I 1 and substrate II 3 arranged on the structural sheet 2, be full of calcium chloride solution in the microchannel, its two ends are communicated with input port 5 and delivery outlet 7 respectively, and nickel alumin(i)um alloy electrode 4 coats whole microchannel with the fluid in the direct heating microchannel.In order to guarantee the insulation of nickel alumin(i)um alloy metal electrode 4 and calcium chloride solution, be the thin polymer film 8 of PI at nickel alumin(i)um alloy metal electrode 4 surface coating materials.Existence because of the manufacture craft error, cause the nickel alumin(i)um alloy metal electrode on substrate I 1 and the substrate II 3 can not contact in good condition with nickel alumin(i)um alloy metal electrode on structural sheet 2 inwalls, therefore, when on substrate I 1 and substrate II 3, making the nickel alumin(i)um alloy metal electrode, make the width of the width of nickel alumin(i)um alloy metal electrode greater than microchannel.

Present embodiment adopts the method for heated by electrodes to form optical waveguide.Nickel aluminum metal electrode 4 is applied steady current, cause nickel aluminum metal electrode 4 temperature to raise, because heat transferred, the calcium chloride solution regional temperature that contacts with nickel aluminum metal electrode 4 in the microchannel raises, make the refractive index of this zone calcium chloride solution reduce, calcium chloride solution in microchannel forms the zone with different refractivity, and the zone that contacts with nickel aluminum metal electrode 4 constitutes fluid overlayer 11, and the calcium chloride solution zone that is clipped between the fluid overlayer 11 constitutes fluid ducting layer 12.

Because nickel alumin(i)um alloy metal electrode 4 coats whole microchannel, when nickel alumin(i)um alloy metal electrode 4 is applied steady current, the refractive index that causes the calcium chloride solution that is in contact with it in the microchannel changes, go up in any direction the refractive index that all satisfies fluid ducting layer 12 refractive index greater than fluid overlayer 11, light beam can be propagated along any direction in fluid ducting layer 12, therefore forms the cylindricality waveguide.

Claims

1. fluid optical waveguide structure, comprise substrate I (1), structural sheet (2) and substrate II (3) successively, have on the structural sheet (2) and substrate I (1) and the parallel microchannel of substrate II (3), be full of fluid in the microchannel, its two ends are communicated with input port (5) and delivery outlet (7) respectively, and pair of metal electrodes (4) is in substrate I (1) respectively and substrate II (3) goes up on the corresponding position with the fluid in the direct heating microchannel; Substrate I (1) goes up and structural sheet (2) is gone up input port (5) and delivery outlet (7) is furnished with perforate on the position accordingly, is used for the input and output of fluid.

2. fluid optical waveguide structure as claimed in claim 1, it is characterized in that: described metal electrode (4) position replaces with on two inwalls that are in structural sheet (2).

3. fluid optical waveguide structure as claimed in claim 1 is characterized in that: described metal electrode (4) position replaces with and coats whole microchannel.

4. one kind as the fluid optical waveguide structure one of as described in the claim 1-3, it is characterized in that: described at surface of metal electrode overlie polymer film (8).