Optical structure for digital microfluidics

Abstract

The optical structure comprises a base, a shell and an upper cover, the base, the shell and the vertex angle of the upper cover are fixedly connected through bolts, a polarization box is installed at the upper end of the base, the section of the polarization box is trapezoidal, an incident opening is formed in the inclined face of the polarization box, a reflection opening is formed in the upper end of the polarization box, and an excitation light source module is installed on the shell. A lens module is arranged at the upper end of the polarization box and comprises a lens barrel, a photosensitive chip and a heat dissipation module, the lens barrel is installed right opposite to the reflection opening, the photosensitive chip is installed at the upper end of the lens barrel, a power module is fixedly installed on the upper cover, and a control circuit is fixedly installed on the base. By arranging the base, the shell and the upper cover and integrating the excitation light source module and the photosensitive chip, the size of the digital micro-fluidic optical structure is reduced, the digital micro-fluidic optical structure is miniaturized and convenient to carry, and meanwhile, the state of liquid drops can be monitored and detected in real time in digital micro-fluidic operation.

Description

Technical Field

[0001] The invention belongs to the technical field of digital microfluidics and relates to an optical structure used for digital microfluidics. Background Art

[0002] Digital microfluidics is a microfluidic technology based on electrowetting or dielectric wetting effects, which precisely controls the movement, segmentation, merging and mixing of droplets on two-dimensional or three-dimensional surfaces. In digital microfluidic operations, real-time monitoring and detection of droplet status (such as position, volume, composition, etc.) is crucial to ensure the reliability and accuracy of the system.

[0003] The current digital microfluidics optical structure has the following technical bottlenecks: bulky size: traditional optical systems usually require complex light sources, lenses and detectors, which increase the size and weight of the equipment; poor integration: most optical systems require external equipment support, and the degree of integration with microfluidic chips is low, making it difficult to achieve portability and miniaturization; high cost: high-performance optical components (such as high-resolution cameras and lasers) are expensive, which limits the promotion of the system; limited resolution and sensitivity: existing systems still have room for improvement in high-precision detection of tiny droplet components. Summary of the invention

[0004] In view of the above problems, the present invention proposes an optical structure for digital microfluidics, which well solves the problems in the prior art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An optical structure for digital microfluidics, comprising:

[0007] A base, a shell, and an upper cover, wherein the base, the shell, and the upper cover are fixedly connected at their top corners by bolts;

[0008] A polarizing box, wherein the cross section of the polarizing box is a trapezoidal shape, the polarizing box is fixed to the upper end of the base, the inclined surface of the polarizing box is provided with an incident port, and the upper end of the polarizing box is provided with a reflecting port;

[0009] An excitation light source module, the excitation light source module is installed on the housing, and the excitation light source module is directly facing the incident port;

[0010] A lens module, the lens module is arranged at the upper end of the polarizing box, and the lens module comprises:

[0011] A lens barrel, the lens barrel facing the reflection port;

[0012] A photosensitive chip, the photosensitive chip is installed at the upper end of the lens barrel;

[0013] A heat dissipation module, the heat dissipation module is installed on the upper end of the photosensitive chip, and the upper cover is provided with heat dissipation holes;

[0014] A power module, the power module is fixedly mounted on the upper cover;

[0015] A control circuit is fixedly mounted on the base.

[0016] Optionally, the lens module includes a switching component, the switching component includes a switching base, the switching base is fixedly mounted with a first servo, an emission filter wheel is fixedly mounted at the output end of the first servo, a plurality of cut-off filters are mounted in a circular array on the emission filter wheel, a switching cover is fixedly mounted on the upper end of the switching base, the emission filter wheel is rotatably mounted between the switching base and the switching cover, the photosensitive chip is mounted on the switching cover, the switching base is provided with a light-transmitting hole, and the laser of the excitation light source module enters the photosensitive chip through the lens barrel, the light-transmitting hole and the cut-off filter in sequence.

[0017] Optionally, the excitation light source module includes a light source bracket, the light source bracket is installed on the shell, a through hole is provided in the middle of the light source bracket, a collimating lens is installed in the through hole, and an LED light source is installed at one end of the through hole away from the incident port.

[0018] Optionally, the light source bracket is fixedly mounted with a second servo, the output end of the second servo is fixedly mounted with a light source filter wheel, a circular array of the light source filter wheel is mounted with a plurality of bandpass filters, and the incident light of the LED light source enters the incident port after passing through the collimating lens and the bandpass filter.

[0019] Optionally, the heat dissipation module includes a Peltier, the cold end of the Peltier is installed on the photosensitive chip, the hot end is installed with a heat dissipation fin, the heat dissipation fin is installed with a heat dissipation fan, and the heat dissipation fan is directly opposite to the heat dissipation hole.

[0020] Optionally, the lens module is fixedly mounted on the housing by bolts, and step grooves are provided at both ends of the housing. When installed, the step grooves are clamped on the outer side of the base and the inner side of the upper cover.

[0021] Optionally, the shell is provided with a cable hole and the heat dissipation hole.

[0022] Optionally, the cross-section of the polarizing box is an isosceles trapezoidal shape, and the two inclined surfaces of the polarizing box are both provided with the incident ports.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. By setting up a base, a shell and an upper cover, integrating the excitation light source module and the photosensitive chip, the volume of the digital microfluidic optical structure is reduced, making it miniaturized and easy to carry.

[0025] 2. By setting the switching component, the light waves entering the photosensitive chip can be controlled by switching the cut-off filter. By setting the light source filter wheel, different bandpass filters can be switched to facilitate the adjustment of the incident light;

[0026] 3. Through the cut-off filter and the bandpass filter, the direct entry of the excitation light can be more effectively avoided, the signal-to-noise ratio of the fluorescence signal can be improved, and the excitation light and fluorescence signal paths can be separated to reduce the background light interference;

[0027] 4. A closed space is formed by the lens barrel, switching base and switching cover to reduce the interference of ambient light. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

[0029] Figure 2 is a schematic structural diagram of a polarizing box portion of an embodiment of the present invention;

[0030] Figure 3 is a structural schematic diagram of a lens module part of an embodiment of the present invention;

[0031] Figure 4 is a schematic structural diagram of an excitation light source module part of an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of the structure of the outer shell of the embodiment of the present invention.

[0033] Figure numerals: 11, base; 12, shell; 13, upper cover; 131, heat dissipation hole; 2, polarizing box; 21, incident port; 22, reflection port; 3, excitation light source module; 31, light source bracket; 32, collimating lens; 33, LED light source; 341, second servo; 342, light source filter wheel; 343, bandpass filter; 4, lens module; 41, lens barrel; 42, photosensitive chip; 43, heat dissipation module; 431, Peltier; 432, heat dissipation fins; 433, heat dissipation fan; 44, switching component; 441, switching base; 442, first servo; 443, emission filter wheel; 444, cut-off filter; 445, switching upper cover; 5, power module; 6, control circuit. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1-Figure 5 , an optical structure for digital microfluidics disclosed in an embodiment of the present invention, includes a base 11, a housing 12, and an upper cover 13. The base 11, the housing 12, and the upper cover 13 are fixedly connected at their top corners by bolts. A polarizing box 2 is installed at the upper end of the base 11. Please refer to Figure 2 The cross section of the polarizing box 2 is a trapezoidal shape. The inclined surface of the polarizing box 2 is provided with an incident port 21, and the upper end of the polarizing box 2 is provided with a reflecting port 22. Figure 1 The housing 12 is equipped with an excitation light source module 3, which is directly opposite to the incident port 21. The upper end of the polarizing box 2 is provided with a lens module 4. Figure 3 The lens module 4 includes a lens barrel 41, a photosensitive chip 42 and a heat dissipation module 43. The lens barrel 41 is installed facing the reflection port 22, and the photosensitive chip 42 is installed at the upper end of the lens barrel 41. Figure 1 The heat dissipation module 43 is installed on the upper end of the photosensitive chip 42. The upper cover 13 is provided with a heat dissipation hole 131. The upper cover 13 is fixedly installed with a power module 5. Figure 2 The base 11 is fixedly mounted with a control circuit 6 .

[0036] Specifically, by setting up the polarizing box 2, the sample is placed in the polarizing box 2, and the light waves emitted by the excitation light source module 3 are incident on the sample surface at a certain tilt angle. The upward fluorescence signal of the sample is collected by the lens module 4 for experimental analysis.

[0037] In this way, by providing the base 11, the housing 12 and the upper cover 13, the excitation light source module 3 and the photosensitive chip 42 are integrated to reduce the volume of the digital microfluidic optical structure, making it miniaturized and easy to carry.

[0038] At the same time, the setting of the polarizing box 2 makes the light waves emitted by the excitation light source module 3 incident on the sample surface at a certain tilt angle, so that the light waves will not directly enter the detection field of view of the lens module 4, thereby significantly reducing the scattering and reflection of the excitation light to significantly interfere with the detection of the lens module 4.

[0039] In some feasible embodiments, the base 11 and the upper cover 13 are rectangular plates, the polarizing box 2 is a trapezoidal box, and the polarizing box 2 is placed on the base 11 and can be fixed by a detachable structure such as bolts to facilitate the placement of samples. Figure 5 The housing 12 is a rectangular housing, the excitation light source module 3 can be selected as a suitable illumination light source to emit excitation light, the photosensitive chip 42 can be selected as a Sony CMOS chip, and the control circuit 6 is bolted to the base 11.

[0040] In some feasible embodiments, the base 11 and the polarizing box 2 can be selected as an integrated structure, formed by processes such as stamping or casting, and the base 11 is located at the bottom of the polarizing box 2 and is set to be an opening so that the base 11 and the polarizing box 2 can partially cover the sample for observation.

[0041] As a specific implementation of an optical structure for digital microfluidics provided by the application, please refer to Figure 3 The lens module 4 includes a switching component 44, which includes a switching base 441. The switching base 441 is fixedly installed with a first servo 442. An emission filter wheel 443 is fixedly installed at the output end of the first servo 442. A plurality of cut-off filters 444 are installed in a circular array on the emission filter wheel 443. A switching cover 445 is fixedly installed on the upper end of the switching base 441. The emission filter wheel 443 is rotatably installed between the switching base 441 and the switching cover 445. The photosensitive chip 42 is installed on the switching cover 445. The switching base 441 is provided with a light-transmitting hole. The laser that excites the light source module 3 enters the photosensitive chip 42 through the lens barrel 41, the light-transmitting hole and the cut-off filter 444 in sequence.

[0042] In general, by setting the switching component 44, the light waves entering the photosensitive chip 42 can be controlled by switching the cutoff filter 444. The cutoff filter 444 can more effectively avoid direct entry of the excitation light, improve the signal-to-noise ratio of the fluorescence signal, separate the excitation light and fluorescence signal paths, and reduce background light interference.

[0043] In some feasible embodiments, the switching base 441 and the switching upper cover 445 are cylindrical shells. After the switching base 441 and the switching upper cover 445 are assembled, a placement space is formed inside. The emission filter wheel 443 is rotatably installed in the placement space. The first servo 442 is fixedly installed at the lower end of the switching base 441. The first servo 442 and the emission filter wheel 443 are connected by a flange. The switching base 441 is provided with a light-transmitting hole. The first servo 442 rotates a suitable cutoff filter 444 to the position of the light-transmitting hole. The lens barrel 41 is threadedly connected to the light-transmitting hole. The photosensitive chip 42 is bolted to the switching upper cover 445. A closed space is formed by the lens barrel 41, the switching base 441 and the switching upper cover 445 to reduce the interference of ambient light. At the same time, a socket is installed at the upper end of the reflection port 22 to facilitate the insertion of the lens barrel 41, thereby further reducing the influence of ambient light and improving the sensitivity of the system.

[0044] As a specific implementation of an optical structure for digital microfluidics provided by the application, please refer to Figure 4 The excitation light source module 3 includes a light source bracket 31, which is installed on the housing 12. A through hole is provided in the middle of the light source bracket 31, a collimating lens 32 is installed in the through hole, and an LED light source 33 is installed at one end of the through hole away from the incident port 21.

[0045] It should be understood that by providing the collimating lens 32 to calibrate the light in the LED light source 33, it is convenient for the excitation light to reach the sample.

[0046] Furthermore, the light source bracket 31 is fixedly mounted with a second servo 341 , the output end of the second servo 341 is fixedly mounted with a light source filter wheel 342 , the light source filter wheel 342 is mounted with a plurality of bandpass filters 343 in a circular array, and the incident light of the LED light source 33 passes through the collimating lens 32 and the bandpass filter 343 and then enters the incident port 21 .

[0047] It should be understood that by setting the light source filter wheel 342 and installing different bandpass filters 343, it is convenient to adjust the incident light, more effectively avoid direct entry of the excitation light, improve the signal-to-noise ratio of the fluorescence signal, separate the excitation light and fluorescence signal paths, and reduce background light interference.

[0048] In some feasible embodiments, the light source filter wheel 342 and the second servo 341 have the same structure as the emission filter wheel 443 and the first servo 442 . The light source bracket 31 is a rectangular box-shaped light source bracket 31 that is bolted fixedly connected to the housing 12 , and the second servo 341 is fixedly connected to the light source bracket 31 .

[0049] As a specific implementation of an optical structure for digital microfluidics provided by the application, please refer to Figure 3 The heat dissipation module 43 includes a Peltier 431 , a cold end of the Peltier 431 is mounted on the photosensitive chip 42 , a heat dissipation fin 432 is mounted on the hot end, a heat dissipation fan 433 is mounted on the heat dissipation fin 432 , and the heat dissipation fan 433 is directly opposite to the heat dissipation hole 131 .

[0050] It should be understood that by providing the Peltier 431 to dissipate heat for the photosensitive chip 42 , the heat dissipation efficiency of the photosensitive chip 42 is improved.

[0051] As a specific implementation of an optical structure for digital microfluidics provided in the application, the lens module 4 is fixedly installed on the housing 12 by bolts, and step grooves are provided at both ends of the housing 12. When installed, the step grooves are clamped on the outer side of the base 11 and the inner side of the upper cover 13.

[0052] It should be understood that by setting the step groove, the base 11, the upper cover 13 and the outer shell 12 are positioned for installation, which facilitates the alignment of the lens barrel 41 and the reflection port 22 and the incident port 21 and the excitation light source module 3 during installation, thereby ensuring the propagation path of the excitation light.

[0053] In some feasible embodiments, through holes are provided at the top corners of the base 11 and the upper cover 13, a through hole is opened on the inner side of the top corners of the outer shell 12, a step groove is provided on the inner side of the lower end of the outer shell 12, and a step groove is provided on the outer side of the upper end. The lower end of the upper cover 13 is concave to facilitate matching with the step groove at the upper end of the outer shell 12, and the base 11, the outer shell 12 and the upper cover 13 are fixedly connected by through bolts.

[0054] In some feasible embodiments, the housing 12 is provided with a cable hole and a heat dissipation hole 131 to facilitate installation of the cable hole, and the cable hole can be provided with a cable interface, including a charging interface, a data interface, etc. The polarizing box 2 can be provided with an isosceles trapezoidal cross section, and both inclined surfaces of the polarizing box 2 are provided with an incident port 21, so that more different light sources can be provided.

[0055] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical structure for digital microfluidics, characterized in that: include: A base (11), a shell (12), and an upper cover (13), wherein the base (11), the shell (12), and the upper cover (13) are fixedly connected at their top corners by bolts; A polarizing box (2), wherein the cross section of the polarizing box (2) is a trapezoidal shape, the polarizing box (2) is fixed to the upper end of the base (11), an incident port (21) is provided on the inclined surface of the polarizing box (2), and a reflection port (22) is provided on the upper end of the polarizing box (2); An excitation light source module (3), the excitation light source module (3) being mounted on the housing (12), and the excitation light source module (3) being directly opposite to the incident port (21); A lens module (4), the lens module (4) being arranged at the upper end of the polarizing box (2), the lens module (4) comprising: A lens barrel (41), the lens barrel (41) facing the reflection port (22); A photosensitive chip (42), the photosensitive chip (42) being mounted on the upper end of the lens barrel (41); A heat dissipation module (43), the heat dissipation module (43) being mounted on the upper end of the photosensitive chip (42), and the upper cover (13) being provided with heat dissipation holes (131); A power module (5), the power module (5) being fixedly mounted on the upper cover (13); A control circuit (6), wherein the control circuit (6) is fixedly mounted on the base (11).

2. The optical structure for digital microfluidics according to claim 1, characterized in that: The lens module (4) comprises a switching component (44), the switching component (44) comprises a switching base (441), a first servo (442) is fixedly mounted on the switching base (441), an emission filter wheel (443) is fixedly mounted on the output end of the first servo (442), a plurality of cut-off filters (444) are mounted in a circular array on the emission filter wheel (443), a switching upper cover (445) is fixedly mounted on the upper end of the switching base (441), the emission filter wheel (443) is rotatably mounted between the switching base (441) and the switching upper cover (445), the photosensitive chip (42) is mounted on the switching upper cover (445), the switching base (441) is provided with a light-transmitting hole, and the laser of the excitation light source module (3) enters the photosensitive chip (42) through the lens barrel (41), the light-transmitting hole and the cut-off filter (444) in sequence.

3. The optical structure for digital microfluidics according to claim 1, characterized in that: The excitation light source module (3) comprises a light source bracket (31), the light source bracket (31) being mounted on the housing (12), a through hole being provided in the middle of the light source bracket (31), a collimating lens (32) being mounted in the through hole, and an LED light source (33) being mounted at one end of the through hole away from the incident port (21).

4. The optical structure for digital microfluidics according to claim 3, characterized in that: The light source bracket (31) is fixedly mounted with a second steering gear (341); a light source filter wheel (342) is fixedly mounted at the output end of the second steering gear (341); a plurality of bandpass filters (343) are mounted in a circular array on the light source filter wheel (342); incident light from the LED light source (33) passes through the collimating lens (32) and the bandpass filter (343) and then enters the incident port (21).

5. The optical structure for digital microfluidics according to claim 1, characterized in that: The heat dissipation module (43) comprises a Peltier (431), the cold end of the Peltier (431) is mounted on the photosensitive chip (42), the hot end is mounted with a heat dissipation fin (432), the heat dissipation fin (432) is mounted with a heat dissipation fan (433), and the heat dissipation fan (433) is directly opposite to the heat dissipation hole (131).

6. The optical structure for digital microfluidics according to claim 1, characterized in that: The lens module (4) is bolted and fixed to the housing (12), and both ends of the housing (12) are provided with step grooves. When installed, the step grooves are clamped on the outer side of the base (11) and the inner side of the upper cover (13).

7. The optical structure for digital microfluidics according to claim 1, characterized in that: The housing (12) is provided with a cable hole and the heat dissipation hole (131).

8. The optical structure for digital microfluidics according to claim 1, characterized in that: The cross section of the polarizing box (2) is in the shape of an isosceles trapezoid, and the two inclined surfaces of the polarizing box (2) are both provided with the incident ports (21).

Images